PHY GEOG LW SURFACES
PHY GEOG LW SURFACES GEOG 2051
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Date Created: 10/13/15
Chapter 1 1222010 93100 AM Geography the study of spatial distribution and spatial patterns of earths surface plants animals climates cities culture etc What Is Where Many reasons why Asked 1 Curiosity people have interest in learning what other places are like 2 Economics where to find spices gold gems best trade and traveling 3 Political Power Spain became rich and powerful shipping bulk loads of gold to America built armies etc trade and traveling 4 Military Power know there own land fight on own land to know and fight on your own land is good source of water etc knowing surroundings 5 Cultural discovery and exploration Expand Modern Practicehigher education Geography became formal discipline in the universities What Is Where through description Maps words Geography s trying to explain to understand why Shifts to question why Are things spaced where they are gold in California not Louisiana explanationexplains why Subdivisions 1 Human Focus on people and what creates culture cities transportation networks and societies 2 Physical Focus on natural world landscapes oceans climates and weather Four Spheres of Geography 1 Lithosphere solid portions mountains beaches valleys continents 2 Atmosphere gas around the world exchange of energy weather 3 Hydrosphere water portions oceans rivers lakes water in atmosphere and Lithosphere 4 Biosphere living world living organisms 5 Common Themes In Geographic Research helps distinguish geographic work from other 1 Location o no such thing as absolute location o starting point everything is located by another location o everything is located with reference to something else 2 Place o characteristics and attributes that make location unique and different from other places o Ex New Orleans 3 Regions c an area that is eternally homogeneous same with respect to some characteristic o ex New Orleans RegionSouth characteristics climate history cultural 4 MovementNetworksConnectionsPathways o things move about the earth goods money air water energy cars follow particular paths 5 Human Environment Interrelationships o people impact the environment deforestation o environment effect people Gustav Katrina Tsunami Earthquake in Haiti Methods and Tools 1 Scientific Methods o method for generating new knowledge a way to solve problemsquestions that no one has figured out o find ideas you can never prove something true o about developing closer approximately about reality 2 Apriori Knowledge preexisting knowledge image of the real world life experiences What we have learnedpicked up forms image of world and how it works Subtotal of life experiences o Gap in knowledge where Scientific Method comes in develops knowledge 3 Theory refers to what generally believed to be correct Steps 1Formulate Knowledge o Provisionalpossible explanation of something but needs to be verified Its an educational guess 2 Testing o determine if hypothesis is true collect data conduct experiments if disapprovedgtreject hypothesisgtgo back form a new hypothesis and start over if acceptedgt fail to disapprove hypothesis now becomes part of knowledge and you found truth System Theory o Applied to people cities natural world o Helps to identify important characteristics of certain things o The basic idea of a system is the set of objects and attributes which are linked together by flows of energy and matter 2 Basic Types o Open System which energy and matter are free to leave ex All systems in nature o Closed System energy and matter are not free to leave THE EARTH IS NOT A CLOSED SYSTEM ALL NATURAL SYSTEMS ARE OPEN Characteristics of Systems o Budget what goes into a system has to add or balance a system or something that comes out INPUTgtOUTPUTINCREASE STORAGE NEGATIVE BUDGET o ex Put every pay check in your account and if you are spending less than that paycheck every month then your account will increase OUTPUTgtINPUTDECREASE STORAGE NEGATIVE BUDGET o ex If you spend more money than you have in your account than you will go broke NO SYSTEMS CAN GROW LARGER FOREVER NOR CAN THEY SHRINK FOREVER INPUTSOUTPUTSCONSTANT STORAGE BALANCEEQUILIBRIUM BUDGET Static Equilibrium input and output stay fixedstationary unchanging Dynamic Equilibrium changing constantly in motion Lag TimePeriod time interval between some change in the environment Change and a system response 0 ex Drainage base rivers don t flood ASAP water has to move through systems before flooding can occurag time Feedbacks the responses of systems to some change that feed back to influence original change Positive acts to encourage or reinforces original change Tend to be destructive nothing can grow forever Negative reduceeliminate negative change Beneficial helps systems preserve environmentally changing O 0 Maps Simplification of what they portray Also represents powerful data storage and retrieval devices shows patterns Maps give a lot of information and can do analysis easier Lots of different types 3 categories o Data Types 0 1Dimensional Data points on a map to show location etc o 2Dimensional Data represents a line on a mappathways connections movements 0 3Dimensional Data areas allow to portray regions political country city states Regions topographic maps temperature maps mountains valleys etc Choropleth display qualitative quality of data data described with words and names Isoline collects points of equal value Distinguish each line itself Quantitative quantity of data Attributes Scales distance and size of map to real life size o Graphic Scale adv can change size of map and scale will still be accurate o Representative Scale numeric form 125000 or 125000 adv easy to use disadv cannot change size of map representation fraction would be wrong o Verbal Scale represent fraction just written in words easy but not accurate if map changes size Review for June 72010 Methods and Tools Scientific Method Improve knowledge better approximation of reality Image of the world o Gap in knowledgeproblems o Formulate hypothesis Test hypothesis observe experiment collect analyze data Accept o Can never prove truth System Theory Conceptual model a System Maps Models of the earth Data types a 1d point location o 2d inearnetworks paths o 3d area continuous distributions 0 chloropleth isoline Scale Graphicbar representative fractions verbal June 8 2010 KeyLegend guide to interpreting the various symbols used on a map critical information about the map DataSource how reliable information s is to the maplocation Orientation North arrow compass rose all four directions pointed out Coordinate Systems used to find locations some maps have these use coordinate system to identify any location using certain coordinates in order for it to work you have to have at least one reference point that is known by the users Latitude series of circles run east west around a globe two reference points for latitude 1 The center of the earth and 2 The equator represents the zero gravity of latitude values of latitude range from 0 equator to 90 North Pole lines of latitude are referred to as Parallels Longitude called meridians run North to South from pole to pole reference Meridian or Prime Meridian is the zero Meridian that passes through Grenache England also use center of the earth as a reference point values range from 0 to 180 East and West Map Projections a method to fill in those gaps and stretch the maps together all projection introduce some kind of distortions Attributes o Distance o Shape o Area relative size of different regions o Proximity basically what is next to what Projection Families all projections have some kind of distortion Cylindrical Projections o Standard linepoint where the paper touches the globe no distortion all attributes are preserved properly Planar Projections Sheet of paper is a flat surface and the standard point is at the north pole Conic Projections Wrap paper into a cone shaped party hat smaller the cone will cut through the globe and get two standard lines excellent for the united States accurate in shape and distances etc Remote Sensing collecting information from a distances without contact Includes monitoring and measuring energy Ex sitting in class we are collecting information without physical contact verbally vision light sound waves Reflected vs Emitting any object that has a temperature above 0 radiates energy Spectrum of Electromagnetic Radiation Diagram that describes a wide range of different kinds of energy in different objects Wavelength distance from one wave to another depends on temperature the hotter the object shorter the wavelength cooler objects give off longer wavelengths Sensors o Passive Sensors require external energy source camera o Active Sensor have internal energy source Radar Observation Platforms most important is airplanes Satellites started in 1970 also an important platform Satellite Orbits o Geostationary Orbit satellites at very high altitudes wont get as much resolutions as the earth rotates so does the satellite just as fast gives constant information about that certain spot o Polar Orbiting Satellites constantly moving over a new location gives picture of the whole world draw backcover at any location will be discontinuous Geographic Information systems GIS basically a digital map makes things so much quicker and easier because of GIS maps has exploded out of geography used in all certain areas business emergency service vehicles natural resources most significant tool o Layerscoverage s each layer there is information about one specific data rivers lakes vegetations Chapter 11 1222010 93100 AM Earth History here 46 Billion years ago Origin of the Solar System described in Planetesimal hypothesis Planetesimal Hypothesis basic idea solar system started as a nebulabig cloud of dust and gasses all material gathered together in one big clump gravitational forces triggered nuclear fusion which lit the sun powers the solar system Geologic Time Scale Time period can be divided into smaller chunks Precambrian start of the earth until a half a billion years ago and started Phanerozoic current geological era the last half billion years Quaternary began 2 million years ago during this period we began to have a sequence of colder periodshuge ice sheets cover large continents changed land imprint on earths landscapes and warmer periods o Pleistocene start of quaternary up until 10 thousand years ago o Holocene more recent warmer period Dating Techniques Relative Dating techniques that let us put things in order at a quality sense age wise oldest dating techniques o Principle of superposition layers of rock oldest rocks on bottom and youngest on top Absolute Dating Techniques allow us to put a specific numeric age on things o Dendrochronology trees add new layer of material count layers and can tell how old the tree is useful problem oldest trees are over a thousand years old cant be used to give any information Radiometric Dating ex Carbon dating relies on fact that some substances are not stable they break down over time and that changes atom into different substance allowed us to put absolute dates on things when mountains were formed etc o Parent Isotope carbon 14 start out with carbon over time those atoms break down and produce daughter isotope Nitrogen 14 rate of break down remains fixed o Half Life each half life you only loose half of what was there never run out of Carbon Classic Philosophies for Interpreting the Earths Systems Uniformitarianims popularized by Thomas Hutton key ideas the present is the key to the past meant you should try to interpret the earths history and how the earth operates today Gradualism simply refers to the idea that a lot of the processes operating to shape the earth occur very slowly and gradually indication of that is that the earth is a very old place Catastrophism the idea that the earths surface is largely shaped by a small number of catastrophes the great flood of nom Channeled Scablands been formed by a giant flood widely accepted today but was rejected in earlier years Earth39s Internal Structures composed by layers three major layers o Core responsible for generating out magnetic field 0 Inner Core composed of metals solid irons and nickel temperature is very hot remain solid density is high 0 Outer Core composed primarily of metals fundamental difference is that its liquid rather than solid cooler temperatures lower pressure and density o Mantle o Asthenosphere plastic texture rock can flow density decreases o Uppermost mantle solid rigid floats in the Asthenosphere o Crust welded together with uppermost mantle make up what is called the lithosphere and float in the Asthenosphere o Oceanic crust more dense relatively thin 0 Continental Crust Lightest materials at surface and densest hottest materials in the core Earth Major Elements o Oxygen 47 o Silicon 27 o Hydrogen 0167 o Titanium 05 o Magnessium o Potassium o Sodium o Calcium Iron Elements cant be subdivided into smaller units Minerals elements that are combined together form minerals ex Oxygen siliconquartz Rocks minerals that are joined together The Rock Cycle o Magma molten rock forms rock through the process of cooling called Igneous Rock o Igneous Rocks rock that forms to the result of magma cooling could get exposed on surface rain sun o Weathering breaks a rock down into smaller bits and pieces called segments o Sedimentary Rock if rock continues to get buried pressure increases and generates heat rock can chemically change which creates Metamorphic Rocks can get remelted and turned back into magma o Metamorphosis the processes of heating and changing of rock Any individual rock type can get recycled and reconverted into any type of rock Types of Rocks Sedimentary Rocks 1 Clastic Sedimentary Rocks formed in theget buried and crushed together this process is called Lithification loose sediments combine to form solid mass of rock o Sand size particles range from about 2006 mm relatively large particles o Silt 006001 mm might be able to see some particles might not be able to see them in the rock o Clays thousandths of a millimeter smallest particle clay stone or a shell o Conglomerate mixture of each sizes of rocks 2 Chemical sedimentary Rocks created by evaporation how salt and limestone are created also created by participation refers to the spontaneous solidification of dissolved materials in water 3 OrganicBiological Sedimentary Rocks named because living organisms because living organisms play a role in their formations coal and shell limestone limestone being formed from shell material oysters clams etc organisms extract Review Remote Sensing o Collecting data without physical contact o Reflected and emitted energy o Electromagnetic energy radiation and spectrum o Sensors passive active o Platforms ground plane satellite Satellites geostationary polarorbiting GIS o Geographic information system c Electronic maps o Layerscoverage s o Rapid analysis expansion of previous abilities The Nature of The Earth Earth History o Origins Planetesimal hypothesis o Geological time scale 0 Precambrian phanerosoic quanternary Pleistocene Holocene o Dating 0 Relative superposition 0 Absolute dendrochronology radiometric halflife parentdaughter isotopes o Uniformitarianism Catastrophism June 14 2010 Igneous Rocks rocks that form when magma cools the rock that forms depends on the particular kind of magma Magma o Mafic magma associated with oceanic crusted material low viscosity thinner effusivegentle eruptions Felsic Magma associated with continental crusted material high viscosity thicker explosive eruptions Viscosity the stickiness of a material Intrusive formed internally inside the crust slow cooling rate because surrounded by rock insulation coarse texture large crystals Extrusive formed externally on surface fast cooling rate on surface no insulation fine texture small crystals Features Pluton deposit of intrusive igneous rock Dyke flat sheet like pluton that forms in a crack or fault of a Pluton Laccolith starts out as a sill becomes dome shaped Latholith largest type of pluton no shape large features Metamorphic rocks rocks changed as result to intense heat and or pressure changes rock chemically Contact Metamorphisms low grade of metamorphism rock altered in contact with igneous intrusion Minerals recrystallize to new forms but not foliation Regional Metamorphism stronger higher intensity large scale deep burial strong foliation and recrystallization of minerals The formation of some metamorphic rocks from an original sedimentary shale Moderate pressure and heat produce cleavage in a slate further increases in pressure and heat give rise to different minerals and types of foliation in schist and gneiss Chapter 12 1222010 93100 AM Endogenic processes processes powered by the earths internal heat constructive create mountains and uplift plateaus Exogenic processes driven by the external energy sources sun break down rocks exposed to the surface solar energy destructive Isostacy large scale vertical movements of portions of the earths crust that result from differences in weight or density Glacial Growth and Decay huge glaciers grow and cover continents 2 miles thick Plate Tectonics the idea that the continents were once a whole Lithosphere is broken up into different plates Plate Boundaries o Divergent Boundaries moving away from each other floor spreading land can create a rift valley o Convergent Boundaries moving together 0 Subduction when convergent happens one layer goes down into the mantle and the other layer overlaps and grows on the top of the other layer o Transform Boundary the two plate slip past each other side by side in opposite direction ex worlds famous San Andres Fault Wilson Cycle describes the life history of an ocean basin o 1 A continent rifts when it breaks up o 2 As spreading continues and ocean opens passive margin codes and sediments accumulate o 3 Convergence begins an oceanic plate subducts creating a volcanic chain at an active margin o 4 Terraine accretionfrom the sedimentary wedge welds material to the continent o 5 As two continents collide orogeny thickens the crust and building o 6 The continent erodes thinning the crust apply to world as a whole called Global Supercontinent Cycle c all earths masses are joined together Earlier Continental Configurations Pangaea Evidence Wegener39s Drift found to can find same fossils on different continents shows that all land must have been connected If you fit the continents together they fit perfectly Evidence Paleomagnetism Stripes study of old magnetic fields o when an igneous rock solidifies metallic materials will orient themselves to the old magnetic field Evidence Radiometric Dating Folding and Faulting o Folding bending of rocks o Faulting o Forces 0 Tension pulling apart rock capable of bending and stretching 0 Compression pushing in towards the center causes folding of rocks 0 Sheer Force not pushing directly in or pulling out pushing in opposite directions but of centered Anticline two limbs folded typography Syncline valleys formed on the sides of an anticline Limb the sides The Dip angle that is made by the limbs with respect to the flat surface Strike the compass orientation of that ridge The Plunge refers to the angle that the crest line makes with respect to the groundflat surface Joint general term for a crack in a rock Fault special type ofjoint in which there has been some movement Normal Fault Tension Thrust or Reverse Fault compression rocks being pushed upwards Strikeslip Fault lateral shearing Orogenesis technical term for mountain formation mountains form along plate boundaries Volcanic arc chain of volcanoes Oceanic Oceanic Oceanic Continental denser plate gets subducted over light continental plate lots of volcanic activity taking place ex Andies Mountains ContinetalContinental both plates are low density so no Subduction very little volcanic activity Himalayan Mountain Earthquakes found around plate boundaries relatively rare California a release of energy when a block shifts spreads out through the ground in the form of seismic waves often occur in groups Elastic Rebound Theory faults are not smooth cuts through bodies of rock they are jagged o Asperities places where rock is stuck together lock rocks together prevent movement eventually one will break and cause earthquake o Focal Point of Earthquake place where asperities gives away o Epicenter point on surface directly above focal point Magnitude Intensity and Frequency of Earthquakes o Mcralli Scale subjective scale based on what we feel and experience o Moment Magnitude Scale Rector scale objective scale measure of the amount of energy that is released during the earthquake logarithmic scale as you go up from one to the next you are using a factor of about 30 o Major Faults So Cal Volcanism Hot Spots Hawaiian islands formed on hot spot large amount of heat escape through Earth s core Sea Mounds submerged Hawaiian islands One of the ways we classify volcanic activity is in terms of how violent the eruption is Mafic gentle eruptions low viscosity Felsic explosive eruptions high viscosity FloodPlatenn Basalts extensive flat sheet of salt that have oozed out of the earth and spread out and covered large areas of earths surface contribute to earths landforms and landscapes Shield Volcano tend to be very broad with sloping sides made mostly of salts largest kind of volcano Composite Volcanoes comprised of layer two different kinds of material magma gases etc explosive eruption o PyroclasticsTephra ash smallest o Lapilli pea size o Caldera crater at surface caused from volcano collapsing mouth o Bombs carhouse size June 15 2010 Continents and Topography Continents are very old Cratons core area of old rock Shield areas where old rock is revealed exposed to surface Accreted Terranes foreign areas of other material that has been welded on Topography Regions overall shape of the land o Earth s landscape are very different o Group areas that have similar kinds of topography o Relief simpler way to describe a landscape difference of highest and lowest areas of the land o Three basic Topographic Regions 0 Mountain Regions high relief confined to two major areas West Coast of South America to Central America and other region across Central Asia Two zones created by plate tectonic collisions 0 Hill and Low Tableland Region not huge mountains hills rolling topography Flat elevated area East Canada South America Africa India and Australia corresponds with Shield regions 0 Plains low relief covers the rest of the continental surfaces areas that are covered with thick plains of sediment that have been eroded off Scales of Landsca peLandformTopography Orders of Relief o First Level major landforms ocean basin continents 0 Time scale in which these landforms change is very slow 0 Very large in size 0 Key processes are primarily Endogenic o Second Level smaller landforms ex Mountain system major plateau Mississippi lowlands ocean trench o Processes are primarily Endogenic Third Level one component of a larger system ex Adirondacks Blue Ridge Mountains Mississippi delta 0 Processes are a mixture of endogenicExogenic Fourth Level smaller component individual mountain Mount St Helen 0 Unique and different from surrounding mountains 0 Process is Exogenic Fifth Level fractions Beach ripple gully 0 Surface processes are dominant Exogenic Chapter 13 1222010 93100 AM Weathering refers to the break down of Earth materials into smaller components Many different processes that can break down material Two kinds Physical Weathering attack earth materials by mechanical forces pushing pulling prying Chemical Weathering attack earth materials at a molecular scale extract individual molecules from the rock Bedrock parent materiallowest largest materials Regolith smaller piece of broken down bedrock Soil exposed materials Controls Rock Characteristics Some hard soft breakable 1 Jointing more joints or cracks cause weathering more surface area the rate of weathering is faster 2 Climate moisture precipitation temperature 0 Temperature hot and cold controls the kind of weathering Precipitation really dryweathering very slow moisture zones strong weathering controls rates of weathering 0 Wet zoneweathering is faster 0 Dry zonesweathering is slower 3 Hydrology the exposure of a certain area to water 0 Example rain falling on a slope to flat area 0 Flat surface water will puddlelonger exposure 0 Slope has little exposure to water 0 A small depression will have a large concentration 4 Topography influences hydrology o Altering microclimates 0 Southern side of a mountains warmer 0 Northern side of a mountain is cooler 5 Vegetation can act to enhance weathering in some cases or can inhibit weathering o Folic acid caused by water that percolates through pine needles Heavy vegetation can protect the earth underlying surface Influence can encourage or reduce weathering O O O Physical Weathering o Frost Action freezethaw relies on water o Root Wedging root presses harder against material and can break material o Crystallization salt depositing into wood and shatters fibers of the wood o ExfoliationSpalling pressurerelease rock swells and as swells it expands and the bonds break once used to pressure underneath the earth surface then become exposed to surfacecauses swelling 0 Cracking layers of rock 0 Rock is exploding Chemical Weathering Processes o Oxidations rusting oxygen from water combine with the metallic in a material material much weaker break easily o Carbonation important with limestone and marble More intense form when water falls to atmosphere gases are in rain drops Karst Topography exposed limestone bedrock Yugoslavia o Pinnacle Karst owes existence to weathering exposed limestone head rocks water trickle down cracks and carries limestone away o Tower Karst result of carbonation attacking limestone bedrock o US Karst more rolling flatter o Sinkholes circular depressions in a surface Some areas sinkholes join together linear sinkholesKarst Valleys look like small river valleys but no river flowing o Caverns underground both erosion in nature and depositional formations are deposition empty space is erosion o Stalactites not things left behind by erosion growing down from ceiling of cavern columns drip stones o Stalagmites growing up from floor of cavern o Drip curtain deposit long and wavy when water drips along a crack long line of rockcollectively known as Drip Stones Chapter 9 1222010 93100 AM Slopes curve or defined surface that creates a boundary of a landform o Interested in steepness 0 Angle 0 degrees to 90 degrees 0 Tangent riserun o Gradient tangent x 100 System Inputs o Input weathering particles creating a slope o Critic steepness called angle of repose steepest slope that gravity can maintain equilibrium state System Outputs o Losing materials downhill mass movements Stability slope remaining in present state or will in collapse o Depends on the forces acted upon the material GRAVITY 0 Force gravity Fg straight down force of gravity 0 Force drive Fd component acting parallel to slopepulling the particle downhill Force Resistant Fr resisting forceholding the particle in place Fr gt Fd stable on a steeper slope Fd gt Fr unstable 0 Friction resisting force holds a particle in place o Shape of particles involved o marble has little friction dice has a lot Cohesion acts to hold the slope in place water is needed o Lubricant reduces friction to allow particles to move o Buoyancy holds up materials o Adds Weight increases the pull of gravity makes slope unstable Slope Elements Waxing portion at the top where the slop is getting steeper and steeper o Freefall face steepest part of the slope o Debris Slope slope getting less and less steep Types of Mass Movement Output of the Slope System Classified by c Speed fast or slow mass movements o Moisture wet or dry o Material water mudflow debris flow o Fall fastest form of mass movement 0 Material leaves contact with the slope 0 Rare because they are very steep slopes o Avalanche material moves downhill and bounces still fast o Flows generally fast but not quite as fast as fall or avalanche o Involves lots of water slurry earth and water 0 A lot of lubrication 0 Friction is reduced o Slides relatively quick but not the fastest 0 Material moves as a cohesive unit o Creep slowest type of mass movement 0 Few centimeters per year 0 Freezing and thawing cause materials to slope down Controls how slopes develop over time Rock strength o Climate o arid environments angular slopes o Humid environments waxing or waning slopes o Process balance balance between input weather and outputs transport Theories of Development Slope Decline argues that slope will continue to get flatter through time Parallel Retreat occurs in arid climates material weathers out of cliff base 0 balance of input and outputs same profile but material is eroded out o Slope Replacement rapid weather profile differs at each stage 0 debris pile grows large and slope forms Global Distribution of Water 97 salt water kill crops rusts metals o 3 is fresh of that is 20 is groundwater of that is 50 deepwater 50 is shallow groundwater 89 is at the surface 99 glaciers and ice sheets Hydrologic Cycle Components o Changes in State liquid gas solid o Sublimation solid to water vapor o Movement getting water from one place to another 0 Vertical up and down precipitation lifting 0 Horizontal sideways flow of water in the ground or rivers o Advection movement of water vapor o Reservoirs places of water storages o Oceans lakes rivers ice sheets clouds biosphere 0 Residence time amount of time that water spends in a reservoir atmosphere days river few weeks groundwater centuries thousands of years c Global Balance matter cannot be created if destroyed 0 Whatever goes in must be balanced by what goes out 0 Budget input output Ground Water more fragile than surface water reservoirs Aquifer body of porous rock that water can flow in and out of container to hold ground water Aquiclude boundaries around an aquifer excludes water helps store it underground Saturated zone portion of the aquifer where the porous bases are completely saturated with water Zone of aerationpore are filled with air water table below zone of saturation where the water is inputs of water recharge come in the form of precipitation some will infiltrate into the ground recharge rate rate at which water is input into our systemto the aquifer by precipitation actually determines how much water we can make use of groundwater mining water table drawdown simply that s there more outputs than inputs water pumping up faster than the water can go so the water table drops aquifer collapse flatteningsquashing as long as pore spaces are filled with water can t collapse water is drawn out so the pores are just air so they collapse aquifer is confined or unconfined o unconfined ground surface above is basically flat and open at the surface allowing water to drain downhigher recharge rates and can make more intended use o confinedonly a small area where the precipitation is allowed to seep down into the aquifer has an aquilude under surface and recharge rate is very slow little rate of movement o makes it to water but does so very slowly o groundwater flow meters per month flow can lead to additional problem cone of depression o when the water table has a sink at a certain spot Where a well is pulling out the water o water being pumped drawn up through mouth of well faster than replacement water can be drawn up through out well pollution problems gotten worse by ground water moving very slowly potentially leach down to underground water o its hard to waterproof something permanently water finds its way around o disperse very slowly nothing is toxic dangerous to health everything is toxic depends on concentration too much salt can kill you too much of vitamin a can poison you it all depends on exposure o more dangerous in ground water solutions because concentration remains heavy for a longer period of time sea water intrusion o freshwater is flowing down though the aquifers and it pushes the sea water out so there will be a balance between sea water and saltwater Example of a groundwater body Agallala high plains North Dakota to panhandle of Texas Largest freshwater aquifer in United States Supplies water to about a 5th of irrigation to crop lands About 13 comes from this aquifer Much of this country is relatively arid arid environmentsangular slopes In 1950s use just took off with central pivot irrigation drill a hole in center long pipe on wheels that will spin great distances in a circle and sprinklers on top water land Became a very new productive way irrigation allowed this land to take off by 1970s there was an excess of 170000 wells all pumping water out of this We will see a lot of people going back to grazing cattle because of irrigation water increase in price greatly Chapter 14 1222010 93100 AM Fluvial Environments o Fluvial refers to things related to rivers one of the transport roots in o Collect excess participation and carry it back to the ocean to balance the oceans water Drainage Basin collects water from a certain area o Drainage divides area of higher elevation that separates two drainage basins How we identify what a river is and its boundaries o Scale independent concept applies across a wide range of different scales Nested Drainage Basin 3 Major Drainages c all precipitation falls east of Appellation Mountains drains into Atlantica Atlantic Drainage c all precipitation falls west of Rocky Mountains pacific ocean Pacific drainage c all precipitation falls in central part of country drains to the Gulf of MexicoeGulf Drainage Drainage Patterns o Dendritic Pattern dendritictree looks like tree branches spreading out common pattern in nature plants use it human circulatory system Most energy efficient way to accomplish taskcollect material from an area and bring it to some location or take material from a location and spread it out 0 Top leftebottom right o Parallel Pattern simple steep slope all channels flowing in same direction o Radial Pattern flow outward from high point dome large mountain o Trellis Pattern parallel ridges and valley spaces folded topography stream capturepiracydivergence of a stream to one valley to another o Deranged Pattern no clear pattern strongly disturbed areas glaciers Water Movement Through a Drainage Basin o Inputs coming from precipitation rain or snow Not all precipitation gets carried away by river systems 0 lst thing that can happen is interceptionesome rain or snow falls on vegetation and can reevaporate before it makes it down to the drainage basin 0 True fall falls through vegetation makes it down to surface of drainage basin could go into storage form a puddleesit there and then reevaporates back to the atmosphere 0 Some may run offerepresents the fastest path way for precipitation to make it into the river system 0 Some could drain down into the ground with all this infiltration 0 Some could go into storagesoak into upper layer of soil and sits until reevaporation or plant roots suck up 0 Some could flow through upper layer of soilefree flow slower pathway 0 Finally some water can drain even deeper down into the ground water could still be supplied to river system represents the slowest pathway Flow in Channels how much water flows through channels Season variations Water sources Precipitation is a major inputs Storm eventseseasonal Higher altitudes melt water Persistent flows supplied by ground water Flow Regime o Mississippi River perennial o Intermittent flow regime where water flows for part of the year and is dry for the other part of the year c Ephemeral water doesn t even flow in the river channels every year several years or a decade or longer Discharge volume of water passing a point in a channel in a given time o Rectangle volume side x side x side o Discharge Q Channel Width x Channel Depth x Channel Velocity o If discharge increases thene width gets wider channel gets deeper or water increases flow speed all happen Exotic Streams River systems where discharge decreases Modes of Sediment Transport Sediment gets carried along with water down ocean sediments deposit make land Erosion refers to picking up particles off of the bed of the river Translocation refers to moving sediment particles to another place Deposition refers to depositing sediment particles somewhere else Modes of Transport mode varies with particle size o Finest particles move in the solution mode of transport dissolves material o Suspension Mode involves larger particles clays float up in water gust in water keep them floating and moving along o Bed Load Transport sands gravels course material maintains some contact with the bed 0 Saltation refers to particles bouncing along the bed in a series of hops o Traction particles maintain continuous contact with the bed roll along the bed Grain Size Velocity Relationships o Capacity total amount of material that it can carry o Competence largest sedimentgrain size that the river can move 0 As river velocity changes it will go up and down with changing discharge o Cohesion o Faster velocity to erode a particle than to keep it Nature of River Channels Braided Stream ex Tasman River NZ o Many channels that separate and come together o Largest annual variation in discharge o Lots of sediment produced by mountains 0 Amounts of precipitation decreases in the winter 0 Amount of precipitation increases in the spring Meandering River o One very sinuous channel that winds back and fourth Developmente don t seem as active as braided channels but can and do migrate Mississippi is continuously shifting migrates around flood plane as a result of meander loops More erosion on outside of river Point Bars area of more deposition on inside of river Oxbow Lake area cut off from main river because of deposits how false river formed use to be Mississippi river it was left behind Floodplain Features formed as a result of a river migrating from side to side 0 Levees ridges of sediment that parallel the banks of a channel 0 Meander scars o Oxbow lakes 0 Bluffs o Yazoo Tributaries often flow down flood plain parallel to main channel before theyjoin the main channel Levees prevent them from joining main channel Longitudinal Profile characteristic of river system controls how much energy the river has to work that intern influences the development of the river system and drainage basin over time Energy rivers have use to transport sediment all ultimately coming from solar energy which causes water to evaporate produces winds which blow water in air causes weather to cool maybe rain Gravitational Potential Energy energy of position energy to do work higher up more energy more work 0 Difference in elevation between head waters and mouth determines how much gravitational potential energy raindrops will have when fall towards base Kinetic Energy energy of motion 0 River tries to see balance between inputs of sediment and transport capacity Equilibrium o Graded Stream transport capacity is equal to supply of sediment 0 Transport capacity and sediment capacity are variable 0 Change in elevation can change how much energy river system has and how much work energy does o Stream Rejuvenation rapid changes lots of work being done to areas underlying by sediments not bedrock period of increased energy and increased activity that results from increase in energy 0 Entrenched Meanders Colorado Plateau o Alluvial Terraces steps of river sediments each pair represents at flood level 0 Nichpoints waterfalls Niagara Falls water flows over nichpoint and water tends to erode and it creates a cave behind the waterfall over time it becomes larger and larger and it becomes unstable and crashes down Deltas are depositional features deposits of sediments that are laid down at the mouth of the river where the velocity of the river flows deepest o Come from Greek letter delta many deltas have a triangular shape o Some are triangular o Mississippi is not triangular o Ultimate form depends on relative balance of the three major process groups that are acting on the landform o Sediment supply supplies input of sediment that is supplied by the river constructional process that tries to build up delta 0 Wave Activity tries to push sediment that is brought down by the ocean back on shore and spread it out along the shore line 0 Tides strong water flows tend to carve up deltas o Sediment Dominated Delta Mississippi River o Wave Dominated DeltaeSao Francisco o Tide Dominated DeltaeFly River 1993 Mississippi Flood Floods o Kill millions of people o Not all associated with rivers o Fluvial floods Flood Prediction o Study to try and predict floods to have warnings and lessen damage o Determine when hurricanes come o Can statistically predict the likelihood of floods 0 Useful and important 0 Flood prediction works by calculating a Recurrence Interval the average time that it takes between floods of a given size 0 Look at largest discharge that occurs each year and rank from highest to lowest then calculate years in record divided by rank 0 RIyears in recordrank 0 Useful for insurance planning to build zoning o Gives degree of predictability that helps plan for floods Flood Hydrograph examine flood characteristics plot of the rivers discharge over time Also show amount of precipitation and response c There is a lag time takes time for precipitation to work its way through the drainage basin to get into the river o Lag time determines how much time we have to plan and get ready for a flood to occur o Many different factors make hydrographs different Nature of vegetationthick clay soils topography Anything that speeds or slows water getting to the drainage basin will alter the hydrograph Chapter 15 1222010 93100 AM Aeolian Processes and Deserts Aeolian refers to things associated with wind AeoluseGreek god of the winds o Important in dessert environments dust storms Wind can be very effective Requirements o 1 We need relatively fine grain material sand size or smaller o 2 Dryair conditions with water wind will not be effective in eroding sediments o 3 Little or no vegetation Where Important o Deserts o Ergs The Empty Quarter sand sea owes characteristics to wind o BeachesSandy Coasts o 60 of coastlines are sandy 0 economic standpoint huge environments o Agricultural Areas people are careful today try to shelter soil 0 Top soil erosion is a large problem in many parts of the world o Loess Regions 0 Loess fine grain material thought to be of glacial origin o Aeolial Sediment Transport 0 Suspension fine grain material dust gets carried along by wind floats in the air 0 Bed Load material maintains continuous contact with the ground 0 Saltation particles bounce along ground like hops most common mode of transport Creep large particles that are moved by the wind In air no solution mode of transport like in water Wind is much weaker transport process than water difference in density air less capable of exerting force in moving grain o Deflation Desert Pavement o Erosional Processes That Result From Action of the Wind 0 O O o Deflation refers to picking up and removal of flying materials Results includes formation of dessert pavements are surface coverings of very course materials to course for winds to move Materials aren t being deposited by wind instead being left behind and new course pieces are left below Another result is the formation of blowouts depressions can range in size from a few meters to several hundred of meters across to a few centimeters to tenths of meters in depth are depressions created by deflation of sand common in coastal dunes o Abrasion when wind throws sand grain against another object wears it down smoothes it out carves it Ventifacts rocks with one or more flat sides that was worn into them by abrasion All of the flat sides tend to face the same way which the prevailing winds are going Sandblasting Yardangs half egg shaped when viewed from side teardrop viewed from above allows wind to flow around with least amount of disturbance Depositional features o Sand Dunes different shapes and sizes 0 Fixed stay in one place stationarydunes with vegetation that lock the dunes in place 0 Mobilized can and do migrate move with wind over time as migrates whole form doesn t pick up and move moves through process of Stoss Slope slope that wind is hitting Slip face builds up to steepest angel where sand is deposited from the Stoss Migrations slow o Specific Types of Sand Dunes 0 Key factors Availability of sediment cant form great big dunes without sediment O H w 5 01 OS Winds direction seasonal shift of wind multiple different directions Barchans moon shaped horn point downwind Form in areas with low sediment availability And areas with single dominant wind direction Add more sand and form barchanoid ridges Ba rchanoid Ridges Sinuous crested Transverse Unidirectional winds As you move up more form as sediment supply increases Grow together and merge to form a sediment crested ridge Form in areas with larger sediment supply Add more sand and make Transverse ridges Transverse Ridge perpendicular Has more sediment supply Crestline is much straighter Crest lines perpendicular to dominant wind Parabolic Dunes Crescent shape moon shaped Difference is that horn points upward Barchans can turn into parabolic dunes Linear or Longitudinal Dunes Key difference orientation of crust line Form in areas with two different wind directions Crest line orients with average of two wind directions Two sets of slip fixes Star Dunes giants of the dessert largest type of sand dunes extend to a Kilometer in height form in areas with very large sediment supplies and different wind directions Fluvial Processes in Desserts Distributions of Desserts 0 Fall primarily in broad latitudinal zones 0 Reason deserts are created as a result of Global Atmospheric Circulation 0 Zones with descending air forms worlds major deserts ArroyoWashWadi river channels in dessert completely lack water water flows brief portion of year or not for several years Ephemeral Stream death valley part of Mohabi dessert entire channel disappears Playa temporary lakes ephemeral lakes Owens Dry Lake in California 0 Badwater in death valley not a playa its essentially a permanent lake 250 ft below sea level feeds off ground water Alluvial Fan looks like paper fan peek ZOO2000 ft deposits build up from rain storm in mountains water flows to valley floor and deposits material Bajada Coalesced Alluvial Fanes extend from mountains to valley floor 0 A set of alluvial fans that have grown together and merged Chapter 16 1222010 93100 AM Coastal Environments Significant environment in human standpoint o Reasons 0 Population Heavy population around the coast lines 23 of population live around coast 0 Activities tourism recreational activity fishing transportation 0 Dynamic Environmentse hurricanes impact coastal line coastal erosion coast lines change very rapidly 0 Young Environmentse coasts are very young o Littoral Zone littoralmarine sediments zone in which sediment is moved around on a regular basis by marine process 0 Depends on energy levels and environments 0 Subenvironments within the Littoral Zone Water Zones n Near shore low energyshallow high energydeep n Surf Zone where water begins to break a Swash Zone very landward edge area covered by water when a wave rushes up beach and then exposed when wave comes back down Land Zones n Foreshore enter tidal zone area exposed to air at low tide and covered by water in high tide n Backshore generally dry where you lay towel on beach may be flooded by storms has sand dunes Two Basic Processes in Coastal Environment Tides Bay of Fundy Tide macrotidal o Flood rise of the elevation of water o Ebs fall of the elevation of water o Tidal Range difference between high tide level and low tide level 0 Microtidal small difference anything up to 12 meter 0 Mesotidal middle anything between microtidal and macrotidal 24 meters 0 Macrotidal Above 4 meters area facing the moon has high tide area facing away has low tidewe go through a cycle of 2 high tides and 2 low tides each day Moon creates 2 bulges in the earth ocean surface Sun creates 2 sets of tidal bulges Experience 28 day cycle in tidal range SpringNeap Tidal Cycle928day cycle during Tidal Range 0 Spring Tides experience highest high tides experience lowest low tide Have largest tidal range earth sun and moon are all being altered 7 Days Later 0 Moon earth and sun form right angle lunar tidal bulges start at low elevation and we get out low tides o Neap Tide lowest high tides and highest low tides smallest tidal range experienced Every 14 days 2 weeks we go into a Spring Tide gravitational cycle between sun and moon Waves 0 0 Wave Crest high point Trough low point in a wave Wave Height Difference in elevation between crest and peak determines how much energy is in the wave Higher wave more energy can do more work Lower wave less energy Wavelength distance between two successive crest or troughs important because strongly influences how deep the wave is Wave heightwavelengthmeasure of wave steepness Wave Steepness Movement of water beneath the waves Wave Period amount of time it takes for one wavelength to pass a fixed point how fast the waves are moving 0 515 seconds open ocean o 23 seconds close to shore 0 1520 seconds good for surfing Wave Generation three factors that determine size in an area 0 Wind Speed faster wind blows more energy transferred to water surface bigger waves built 0 Duration of wind time that energy is transferred long timebigger waves Fetch distance of ocean water available for the wind to blow across Oregon and Washington state have about 4000 miles of ocean wind can blow across Tremendous amount of energy in waves driven by solar energy o Solar energy creates wind friction on ocean surface cause ripples and waves o Movement of Water within Waves 0 O 0 Wave Orbits water depth of about half the wavelength circular motion continues down below surface of water diameter gets smaller the deeper you go the smaller the diameter the slower the water particles move Takes one wave period to complete one of these orbits Shoaling 1St wave begins to slow down speed decreases 2nd wave length decreases 3rd wave height increases 4th wave steepness increases wave becomes steeper until wave breaks and water surges forward Wave Refraction changes the distribution of wave energy on the shoreline Important in shore line development wave crest bends around and tends to focus energy net result is wave crest is spread over large area energy level on coast line very low Tends to smooth out the shore line and develop it to be parallel to the on coming wave crest Alongshore Currents horizontal currents can transport tremendous amounts of sand Beach Drift sediments are being pushed along shore o Tsunami O Generates by something that displaces water form below Marine earthquakes Major underwater submarine landslides Low height long wavelength Long period Problem is wavelength could be up to 100 Kilometers o Trough leads 0 1St thing you see is water dropping and you see water being drawn outwards Coastal Landscapes and Landforms Materials rocky sandy muddy Primary Coastline owe character and nature to terrestrial processes 0 Ria coastlines drowned river valleys 0 Delta Coastlines created by terrestrial processes and river bringing sediment down and depositing o Fiord coastline similar to Ria old river Secondary Coastline o Wavecut cliff Result of wave based erosion o Barrier Islands marine deposition 0 Reef Coastlines 0 Wave cut cliffs Erosional Landforms o Arches waves are cutting away at land 0 Stacks remnants of arches Depositional Landforms o Beaches extremely active profile change on regular basis place along coast where sediment is constantly in motion often go through Storm Fair Weather Cycle Storm Fair Weather Cycle n Swell low steepness a Net onshore transport a Wide beach Relatively steep foreshore slope a Storm seasone waves crash into beacheswaves relatively short but quit energetic high energy levels High steepness cause a net offshore transport of sediment Final profile during storm period looks narrow back beach and relatively flat foreshore zone positive in nearshore bar o Depositional Features 0 Spit created at locations where there is a sudden change in coastline waves cant fold around corner fast enough to push sediment around Straighten outs shoreline Tombolos also created by alongshore transports perpendicular to shore build up land bridge created between tombolo and the beach Barrier Islands long narrow ridges of sand run parallel to coastline couple 100 kilometers in length common in United States run east and west coast o Dynamic features naturally change over time 0 O Subenvironments Ocean side flat beach high wave energy levels Beach recreation area sand dunes Dune ridges Landward side salt marshes steep beaches sheltered low energy level narrow body of water bay lagoon no waves calm enough for marsh grass to grow Barrier Island Rollover when sea levels rise islands respond by migrating inland narrow strip of land little or no vegetation left on it Overwash Fan Large waves come in a pick up sand and spread over land Barrier Island Formations Theories Spit Extension spit that grows along one edge of shoreline breach spit gets cut by a storm and separates from mainland Drowninplace some point in past when sea level was low developed dunes and features as sea level rose and higher land features appear as barrier islands Emergence theory idea that wherever you have a location where two marine currents run into each other they slow each other down and whatever they are carrying they drop and it builds up making barrier islands o Biological Landforms living organisms that influence landforms o Coral Reefs mostly nonliving structure calcium carbonate limestone exoskeletons of living corals Distribution warm temperatures 030 North and South Lots in Western Pacific few in Eastern Pacific Gyre circular pattern of currents in an ocean basin Shallow water need bottom to attach to most live with algae Cant tolerate high levels of sediment Development of Coral Reefs hypothesized by Charles Darwin n 1 Fringing Reef platforms of surrounding corals rock hugs shoreline n 2 Barrier Reef separated from volcanic island called a lagoon n 3 Atoll no main land circular ridged shape Human Impacts o Populations on coast are increasing o Sea level is rising which allows individual storms will be able to penetrate further and further in land 0 Result contributes to erosion Big problem o Dealing with Erosion Problem 0 Involves building structure at shoreline and have one of two basic purposes 1 Intercept or designed to redirect sediment transportation 2 Reduce wave energy levels and sediment 0 Shore Walls prevention of erosion o Groins shore perpendicular walls intercepts sand being transported by alongshore currents Sediments are blocked and accumulate along the beach Problem down drift has no sand and is still eroding 0 Break Waters Shore parallel walls idea is that waves will break on wall and use all energy and energy at shoreline will be reduced o Jetties shore perpendicular walls installed to try and fix and inlet in place Problemse causes erosion on one side of the coastline 0 Soft Protection Methods trying to work with nature adds sand and replace material that is being lost because of erosion Beach Nourishment pumping sand into a coastline location Problem expensive because it does not fix the underlying problem a Dune Restoration sand fences planting dune vegetations Retreating moving further inland to avoid restoration Understanding that we can beat nature but should work with it Chapter 17 1222010 93100 AM Glacial Environments Cryosphere o Includes areas covered by glacial items ice sheets o Also areas underlying by permafrost permanently frozen ground o Its geography is controlled by climate Permanently frozen ground cool o Climate System 0 Global Energy Budget Inputssolar energy from sun a Sun rays directly shine on equator same ray of sunshine is spread over large surface area around equatoroblique Outputslong wave of radiation that the earth is constantly giving off heat Change in storage a Amount of energy in storageTemperature the energy that stores in that object a Hotlots of energy a Coldless energy Special distribution of energy in an area is variable o Climate History 0 Global temperatures were very constant and warmer than today 0 12 billion years ago the earth started going through long periods of cold weather and then would alternate to long periods of warmer weather and so on Ice Ages cold period Quadranary period temperatures began to get colder than before Glacial periods ice sheets form Interglacial periods temperatures warm up and ice sheets melt back Reached present temperatures 10000 years ago began the Holocene period climate period we are in now So many factors involved in global climate we still don t know everything about it Area of infancy science o Milankovitch Cycles nature of earth orbit about the sun and variations in it over long periods of time o 1 Orbit elliptical circle amount of ellipticality varies over a cycle that takes 100000 years 0 2 Tilt axial tilt 40000 year cycle that angle controls the strength of seasonality More tiltedmore annual variation there is at daylight More seasonality more energy shifting o 3 Wobble 26000 years direction of the earths axis o Other scientist concluded that the variations of the Milankovitch cycles don t move enough to cause temperature changes that we have experienced they seem to act like triggers c As continents shift around they cause Glaciers o Distribution massive ice sheets covered most of Canada and North United States 2 miles thick 0 Most ice found in ant artica 90 0 Rest is in Greenland 89 0 Remaining is scattered around on high mountain peaks around the world c To Form 0 You need to have snow that persist on a year round basise snow pack gets thicker weld it together to form ice granules called firn granules 0 Can form glacial ice at any latitude Go up in atmosphere temperature goes down Decreases 67 degrees Celsius every 1000 meters you go up 0 Snowline line at which ice firns begin to develop at higher altitudes Relatively high 0 Have to drop temp cool enough so snowline can o BudgetseMaterial Budget additions and removal of materials in glacier ice 0 Inputs new snow 0 Outputs melt water 0 Accumulation Zone Elevation above the snowline O O Ablation Zone below the snow line Advancing Glacier Positive budget more material in accumulation zone glacier grows larger Retreating Glacier negative budget more material melting than new material being added glacier growing smaller moving back up valley Stagnant Glacier balanced budget new materialmelted material o Movement 0 Brittle zone upper most layer hard rigid cant bend and flow cracks shatters and breaks Ice in freezer Plastic Zone underneath brittle zone bend stretch move brittle zone weight prevents from cracking Ice tends to bend and stretch downhill called Internal Deformation one of two mechanisms that help ice to flow and move Second mechanism is Basil Slip slipping along melting down at base of glacier as result of friction or pressure melt water acts as lubricant and causes it to slip Slow rates Glacial Surge glaciers leap forward few hundred meters per month related to build up of melt water o Erosion two mechanisms 0 0 July 6 2010 Plucking glacier flows over rock there is a lot of friction and heat and tends to melt as glacier moves down other side of structure friction lessens and heat dissipates and glacier re freezes Water melts over and then refreezes Glacial Abrasion result from the material freezing to the surface scratches against a glacier grinding against solid rock Alpine Landforms o Preglacial time passes and temperature drops snow persists on a year around basis move snow accumulates glacial ice takes place o Glacial more time passes negative budgets retreating phase occurs o Postglacial o Cirques Bowl shaped depressions created near mountain peaks o Tarns lakes that form after the glaciers melt joined together by small streams o Paternostergroups of tarns o Ar tes arrow jagged sharp ridges sharp knife like ridges that now separate valleys o Horns jagged peaks pointed mountain tops jagged spires o Glacial trough U shaped result of all material scrapping o Hanging valleys Where small valleys meet larger valley enter higher up on the wall All transformations produce sediment called glacial drift Glacial Drift o Till mixture of all different sizes of material deposited directly by the ice o Stratified drift sorted into layers of distinct grain sizes laid down by the melt water that flows out from the glacier carries sediment with it Material far away from the glacier was probably carried by stratified drift o Moraines ridges created from till 0 Terminal Moraine formed furthest away from where glacier originated material dropped from glacier formed when glacier was at o Recessional Moraines marked positions where glacier was stagnant for a while 0 Lateral Moraines form as result of material that falls off valley slopes o Medial Moraine where two glacial ice stream meet it is the meeting of two smaller glaciers formed in the middle of the valley Continental Landforms much larger o Outwash Plain o Till Plain Recessional Moraine Esker sinuous ridges like a big snake running across the lands are basically inside out river beds created by old river beds that were running on surface at the base or within a glacier often carries a lot of sediment kame small irregularly shaped hills formed as result of sediment that gets washed into depressions low place on surface when ice melts out sediment gets dropped at that location and forms a hill Kettles small depressions that contain water inside out origin created when sediment is deposited around a chunk of glacial ice once ice melts you are left with a kettle lake Drumlin stream lined hills depositional features formed of sediment that is laid down underneath the base of glacial and as glacial ice flows over sediment it is formed into groups swarms of drumlins Roche Montonnee formed by erosional process carved into bedrock sediment abrades the glacial material Periglacial Enviornments near glacial aren t glaciated but close to underlined by permafrost Two basic types of permafrost Continuous permafrost special find it everywhere occurs at highest latitudes with coldest temperatures Discontinuous Permafrost more and more patched lower latitudes Active Layer is the top layer of permafrost that thaws out during the summer time less than 12 meter Gets thicker as you move more towards the south 0 Taliks areas where ground isn t frozen occur in association of bodies of water Acts like a blanket and prevents ground from getting cold Dominant processes that act in these environments Frost Action relatively large areas ofjaggered rocks 0 Block Fields jagged angular rock freezing water causes rock to expand and crack Ice wedge small crack in ground water trickles in crack when freezes water expands and enlarges the crack and repeats ultimately form ice wedge Patterned Ground ice wedge polygons on surface of ground under laid by ice wedge from growth and expansion of ice common in periglacial environments Cryoturbation large rock expands and part break off and fall underneath and rock eventually is pushed up and cause the patterned ground Chapter 19 1222010 93100 AM Ecosystem Fundamentals o Biosphere Area of study of biogeographers interested in spatial distribution Ecology nature of organisms and the way they exist Ecosystem a set of living organisms and there abiotic or non living surrounding that are linked together by flows of matter and energy o Biomes largest ecosystems we deal with Energy Flows Photosynthesis o Solar energy sun and plants are primary producers in ecosystem can fix energy and store it in a chemical fashion Autotrophs fix own energy source Gross Primary Productivity total amount of energy that the plants fix Net Primary Productivity the left over energy that the rest of the ecosystem uses after the plants use there energy o GPPenergy that plants useNPP Energy flows NPP o Forests most productive o Grasslands intermediate o Extreme environments least productive More vegetation there is more productivity wet areasmore productive areas Energy Flows Food Chain o 1st Trophic level autotrophs primary consumers o 2 d Trophic Level herbivores organisms that get there energy source by consuming plants and inheriting the plants energy that was stored consumers rather than producers primary consumer o 3rd Trophic Level Carnivores secondary consumers get energy by consuming herbivores and inheriting energy second hand o 4th Trophic Level top carnivores tertiary consumers o 5th Trophic Level heterotrophs decomposers fungi and bacteria energy from the waste products or remains or other organisms Energy Flows Food Web Food Web multiple pathways of organism at the same or different trophic levels 10 Rule some energy is lost and degraded into nonuseful forms energy that is lost at each trophic level on average only 10 of energy that is fixed will get passed onto the next trophic level Matter Flows Nutrients o Nutrients substances organism need to support all the biological processes going on inside of them 0 Macronutrients Carbon Oxygen constant supplies in order to maintain life things organisms need that come in massive amounts Micronutrients need in tiny quantities multivitamins could be poisonous in large quantities Zinc Baron Copper o Biogeochemical Cycles pathways that nutrients follows as they are shifted between reservoirs O O O Collected pathways that any nutrient follows Every nutrient has its own biogeochemical cycle Found in reservoirs in biosphere hydrosphere lithosphere etc People can alter the fundamental operation of these cycles on regional or global basis Carbon Cycle among reservoirs in cycle we have carbon stored in atmosphere ocean biosphere lithosphere Stored as gas oil and coal One of the primary pathways that carbon follows is through breathing Animals breathe out C02 and plants take it in We can alter this cycle by burning fossil fuels Nitrogen Cycle most common gas in the atmosphere and most common form is N2 Most living organisms need nitrogen in form of nitrites and nitratesnitrogen atom with some oxygen Lightening strikes a 1 form of how nitrogen gets converted to a form we can use a as a bolt moves through atmosphere it super heats air that surrounds its pathway which causes many chemical reactions to create nitrates or nitrites Nitrifying bacteria a Live mostly in the soil n More important process that fixes nitrogen in useable form Cultural Eutrophication people over feed a Fertilizer inputsexcessgets into water body causes algal bloom bacteria bloom and results into dissolved oxygen levels If oxygen levels drop enough causes fish kills a Dead Zone void of light result of eutrophication spring farmers fertilize fields and excess works its way into the Mississippi River and carries it to the Gulf in the spring and organisms have to migrate out or they die Two mechanisms nothing is poisonous and everything is poisonous concentration of exposure too much of something is not good o Bioaccumulation results from fact that some substances will build up in living organisms o Refers to the tendency of some substances to accumulate in living organisms Especially fat soluble substances ex Vitamin A Large doses of Vitamin A over a period of time can make you very sick o Biomagnification 0 you are what you eat 0 get exposed to accumulative dosage of everything that you eat and everything that you eat gets exposed to what it ate Can increase our exposure to toxic material Tendency for concentrations to increase and we move up the food chain Concepts Population and Community o Population members within the individual species bull head shark population in Mexico 0 O O Community a group of species that share some portion of the environment along lake Ponchatrain grasses Habitat nonliving surroundings that and organism acquires a place where it lives shelter Niche function role that an organism plays in that ecosystem place on food chain can only have one organism occupying a niche 0 Competitive exclusion principle two organisms are trying to occupy same niche one will be better suited or will out compete other organism for that niche one will be better for that particular niche shellfish Mutualism relationship that is mutually beneficial for both organisms Parasitism relationship where one organism benefits and the other organism doesn t mosquito s and people when one organism feeds off of or lives on other organism Tolerance range of conditions an organism can tolerate or with stand some plants can live in freezing climates other may not survive a freeze 0 Optimum Range range in which the organism will thrive climatic conditions food availability Limiting Factor these conditions determine where organisms can and cannot survive or thrive Stability refers to an ecosystems ability to preserve itself when surrounded by change sometimes disasters change conditions 0 Grass lands preserve selves by developing resilience ability to survive these changes springs back after disaster 0 Inertia ability to resist change different approach to responding to changing conditions red wood cant burn Succession refers to a sequence of different communities that occupy and area after a major disturbance abandoned farm u 1 6 97 Salt water Saline b 3 fresh 0 22 groundwater 12 deep 0 z shallow 6 778 ice glaciers and ice sheets 0 02 rivers lakes atmosphere clouds soil 0 Changes iurstate O Melting freezing O Evaporation condensation O Sublimation direct change from solid to gas or the reverse 0 Movement 0 Vertical evaporation lifting by winds form clouds precipitation 0 Horizontal advection surface runoff channelized creeks and rivers Reservoirs residence time average amount of time water spends there atmosphere residence time a few days rivers few weeks ocean a few thousand years 0 c Global budget see gure in book O O O O O O Groundwater Supplies about 20 of our water use in US Aquifer stores water Aquicludes water cannot penetrate acts as oor or walls Saturated zone part of aquifer that is completely filled with water Water table upper part of saturated zone Zone of aeration above water table empty part of the aquifer Ground ate 9 Rechalge rate the rate at which new Wateris being supplied t0 groundwatel comes cm pIecipimtion detetmined by climate l COn nedrlOWEI Iechalge Iates tend t0 have an aquiclude abcve itheventing new Watet l Unccn nedr higher lechalge rates ohmin WateI um WateI um sail I WateI mble dIawdawn gmundwatel mining I Cone of dCPIESSiO r Watet is draining Out mole Iapidly fasteI than the wateI can aw hmizcntally to Ieplenish the Watet supply b Aquifel collapse OCCUIS when wateI is chained out and the weight of oVeLlying matelial is too heavy 6 Rate of movement could be 2 meters per week month year contaminants cannot move around and are left in large concentrations 0 Salt water intrusion penetrates land when freshwater is pumped out O O O Ogallala lains Largest freshwater aquifer in N Anierica throughout 8 states South Dakota through Texas Responsible for 15 of irrigation Central pivot irrigation well in the center of a circle pipe with sprinklers rotates around watering crops Came from glacial meltdown would take over 1000 years to recharge Over half of the water supply in Ogallala will be gone by year 2020 O O O O Channelized ow Water sources storms meltwater groundwater ow regimes Sediment transport erosion translocation deposition n1odes solution suspension bedloadtraction saltation competence capacity Grain size velocity relationships Large faster except fine Faster to erode than transport transport than deposit O O Channel types braided multiple channels large sediment supply visible discharge Meandering formation migration of meanders oodplain levee oxbow lake meander scar yazoo tributary Stream gradients longitudinal pro le gravitational potential and kinetic energy graded stream equilibrium base level change rejuvenation downcutting entrenched meander alluvial terrace nickpoint resistant outcrop waterfall Deltas velocity drop at mouth competencecapacity drop deposition deltas depositional feature sediment supply wave energy tidal currents O Flooding o Nicoinli er z 7 a 39 3gwund7i t s not perfectly smooth caused by stronger rock more resistant to erosion O Waterfall caused by a nickpoint causes erosion at the bottom of the waterfall cave forms behind waterfalls from erosion overlying material collapses this process repeats itself smoothing the surface 6 Niagara escarpment O V Deltas deposi al res deposit39sedimentwat the mouth of the river name comes from Greek letter A due to triangular shape Controls 0 Sediment supply 0 Waves and currents 0 Tidal ows Mississippi delta sediment supply dominated system low levels of Wave energy 1 ft height low level of tidal ow Sao Francisco delta Brazi1 wave dominated sediment picked up by Waves small number of distributaries Fly River tide dominated must have wide channels or very fast moving Water in small channels which eventually erodes them and makes them Wider Flooding 6 Recurrence intervalv historical records of a given river can be used 9 to plan an mmmnz e damage 0m ooding needs a lot 0 accurate data to actually be useful Flood hydrograph shows two graph rainfall record peak discharge Drainage Basin characteristics 6 0 Size Vegetation amount and type Soils Topography Needlepoint7 Aeolian Processes and Deserts A Dust 130er r 39 39 0 Sand size or smaller material 6 Sparse vegetation wind must be able to getto sediment 0 Low moisture levels no forces holding material together Air is about 1000K less dense than water but is faster moving 6 Where 0 Ergs the empty quarter 0 Sandy coasts 0 Agricultural areas 0 Loess regions coarse siltsized material glacial origins Aeolian Sediment Transport Modes 7 0 Suspension held up in the air best for sedimentsized O Bedload A Salmtion most important for sandsized 6 Creep hits the ground as wind pushes it 6 No solution mode 0 Density difference 6 De ations picking up particks fran surTace carrying them off somewhere to be deposited 6 Desert pavement lag surface protective covering of large pieces of rock protecting them from wind 6 Blowouts bowlshaped depressions created by de ation common in coastal dunes 6 Abrasion wears away material sand has rough edges 6 Ventifacts rocks or another land feature worn away by the abrasion of sand grains wind direction can be seen by slope of abrasion 0 Yardangs protruding rock from ground sloped from abrasion lets wind ow easily around it tearshaped from above 6 Sand dunes 6 Fixed 7 agent acts to hold sand in place usually that agent is vegetation O Mobile 7 sand moves With Wind 6 Dune migration can move meters to 10 s of meters per year 6 Stoss slope gentle slope 0n the upwind side b Slipface steeper downwind side 6 Dune erodes in layers off the top by winds Types of Dunes 77 7 shaped duneghorns point downwind small Barchanswresgent sediment supply 0 Barchanoid ridges individual harchans that have grown and merged together creating ridges sinuous crest small sediment supply but larger than barchans moderate unidirectional winds O Transverse ridge straight crest made with even more sand which is why the ridges are straighter O Parabolic dune crescent shaped horns point upwind horns are xed but middle sand is still exible horns become very long O O Longitudinal or linear dunes moderate to large amounts of sediment ridge formedparallel to wind formedbecause of two wind directions Star dunes star shape largest type of dune by far can be thousands of meters tall very large sediment supply multiple wind directions Controls 011 Dune Types 6 Sediment availability marchans 6 Directional variability of Wind O Deserts Distribution 2040 Nandslatitudes r 7 Dry channels 1 only carries chci 6 Anoyo Wash Wadi Owens dry lake 0 Playa O Badwater Alluvial fan fan shaped pile of sediment stream carries sediment down mountain changing route may times Where canyon meets oor very steep Bajadai coalesced alluvial fans Exam 2 Study Guide 11112010 124400 AM WATER RESOURCES 97 Salt water Saline 3 fresh o 22 groundwater o 12 deep 0 12 shallow o 778 ice glaciers and ice sheets o 02 rivers lakes atmosphere clouds soil quotL i i 1 Li 395 39 Groundwater below the surface of the soil more fragile than surface water reservoirs and easier to contaminate o Supplies about 20 of water in US o Aquifer body of porous rock that water can flow in and out of container to hold ground water 0 Unconfined ground surface above is basically flat and open at the surface allowing water to drain downhigher recharge rates and can make more intended use o Confined only a small area where the precipitation is allowed to seep down into the aquifer has an aquiclude under surface and recharge rate is very slow little Saturated Zone Lower portion in aquifer where the porous spaces are filled with water 0 Zone of Aeration upper portion of aquifer above the water table where the porous spaces are filled with air 0 Water Table top upper most part of the saturated zone Aquiclude body of rock that doesn t allow water to penetrate helps store groundwater Recharge Rate rate at which water is input into our system to the aquifer by precipitation actually determines how much water we can make use of Rate of Water Movement 0 Groundwater movement is much slower depending on how porous the material 0 The various slow rate of movement can cause a number of problems 0 Contaminants cannot move around and are left in large concentrations o Cone of Depression 0 A local depression of the water table around the well Water is being removed from the aquifer faster than it can flow horizontally through the rock to be replaced 0 Wells will be forced to reduce pumping rates 0 O quot lhi ill39l39quot 39lmj o Ogallala Aquifer O O O O O O O O Largest freshwater aquifer in N America Covers portions of 8 states South Dakota through Texas 12 million square km Responsible for 15 of irrigation in US Over 100000 wells recharge slowly Originated from glacial meltdown Would take 1000 years to recharge what we have used Experienced water table drawdown Expensive to pump deep groundwater not a solution 11112010 124400 AM RIVER SYSTEM S b l il lm l 39 m j u plgl lv l i l1 Major US Drainage Basins o Pacific Drainage everything west of the Rocky Mountains drains into the Pacific ocean Atlantic Drainage everything that is east of the Appalachians drains into the Atlantic Gulf Drainage everything central drains down into the Gulf of Mexico Drainage divide area of higher elevation that separates two drainage basins How we identify what a river is and its boundaries Interception some of the inputs land on the vegetation of the earth leaves grass and get reevaporated Throughfall the remaining precipitation that makes it to the ground falls through the vegetation and makes it into the basin Runoff Will runoff over the surface and collect into sheets and layers the fastest pathway for water to make it in a channel Infiltration penetrates into the ground Throughflow Some of the water can flow through the uppermost layers of the ground and make it into a net pathway The portion of water that infiltrates down in the ground and flows through the soil to the nearest channel Groundwater Water that trickles down even deeper o This water may also ultimately make it into a channel Provides base flow to many rivers with its consistent long term input of water Drainage Pattern li ilnL39 39liquot Lil furl Flow in Channels o Meltwater occurs in the spring o Storms can be seasonal input o Groundwater persistent base flow Flow Regimes o Intermittent Regime 0 Water only ows for part of the year ex Southern Cal o Ephemeral Regime 0 Water flows in occasional once every few yearsdecades 0 Extremely arid regions Discharge o The volume of water moving through a river per unit of time o Water is in form of a rectangle and discharge depends on volume of the box Q discharge W x D x V water velocity how fast the water is flowing o Will have more discharge at the base of the drainage basin o Will have less at the head of the basin c Q almost always increases as you move downstream more area o The W D and V will get larger which makes Q larger Exotic Streams o Streams in which discharge decreases as you move downstream o Water is removed through evaporation or human activity o Colorado River Nile River Sediment transport o River streams also carry huge quantities of sediment through running water Divide into 3 components o Erosion o Refers to picking up the material o Translocation o Refers to moving particles from one place to another o Deposition 0 When the particles are deposited Capac y o The total amount of sediment a river can transport Competence o The largest grain size that a river is able to transport Grain size velocity relationships o Larger grains faster velocity except fines cohesion silts clays o Faster to erode than transport transport than deposit Mode of Transportation o Determined by size of sediment and speed of running water o Solution o Finest particles carried by rivers dissolved minerals individual ions can deposit a tremendous amount of material o Suspension Particles basically flow in the water o Bed Load o Particles maintain some degree of contact with the riverbed o Saltation Particles hop along the ground in little jumps 0 Traction Very largest particles roll along the bed the water cant put enough force to push them up Channel Types Braided Channel o Set of multiple channels that twine back and forth merge and separate flowing around deposits of very coarse material like gravel o Tend to be found in areas with very large sediment inputs into system mountainous areas glaciated mountain areas snowy areas o Patterns can change over time o Large sediment supply variable discharge Meandering Channel o Tend to be an individual channel that winds back and forth lazily o Migrate move over time as the meanders grow largersmaller o Curvature is when the distance on the outside is larger than the distance on the inside water will have to flow faster on the outside which make lead to erosion and cutbanks o Slower flows on inside of curve which encourages deposition 0 Point bar develops on inside of curve shifting the meander o Ex of positive feedback when meander changes direction causing water velocity to become faster Meander loop when a meander of the river gets unattached and is left behind to form an oxbow lake ex false river Floodplain o Meandering rivers tend to migrate from side to side and create a zone 0 Meander Scar The final stage in creating a meander swampy areas 0 Levees Naturally occurring features that influence river behavior Ridges of material that run along banks of river that get deposited there during floodplains Increase the crosssectional area of a river 0 Yazoo tributaries Smaller streams that feed water into a larger river Run parallel to the main channel until they joint it this happens because of the levees Stream Gradients o Refers to the steepness of the channel o Headwaters close to the drainage divide have a relative steep gradient the 0 When a raindrop falls near the drainage divide it has this 0 Gets converted into kinetic energy motion energy that can move sediments o How much energy a river has depends on elevation difference between headwaters and base level elevation of the mouth 0 River s ability to transport sediment is going to the be the difference in elevation 0 Elevation can change sea level could fallrise o Stream Rejuvenation 0 Any way to knock stream out of equilibrium and stream is downcutted into drainage basin o Entrenched meanders o Meanders than have been carved down into the bedrock o Tremendous amount of uplifting which adds energy to the river flowing process which causes downcutting 0 Ex Colorado Plateau o Alluvial Terraces 0 Terrace Series of steps running of the side of the valley 0 Alluvial Made up of sediments deposited by rivers 0 Gone through a series of down cutting where material cuts away all of the material in the ground and starts migrating to other parts of the plain and starts cutting out material over there 0 Then there is another period of down cutting and horizontal migration takes over and enters a period of equilibrium and creates a new terrace o Nickpoints 0 Small little bumps that are scattered o Resistant outcrop waterfall o Occur in drainage basin at places where river flows across nonresistant material 0 Location where we find waterfalls in river system 0 Over time rivers try to remove nickpoints by wearing away these materials Tend to form a little cave in back of the waterfall occurs in all waterfalls The cave will get larger and larger until it cant support itself and comes crashing down The process begins over again with a new cave Each time the nickpoint gets higher until it disappears and there is a smooth profile Ex Niagara Falls Niagara escarpment creates the nickpoint in the drainage basin 0 o Sediment supply from the river 0 More sediment larger delta 0 Most dominant process 0 Ex Mississippi River o Wave Activity 0 Waves will pick up all of the material and plaster it along the shoreline o In wave dominated deltas you end up with a more triangular shape with distributaries smaller channels that supply water to a channel flowing into the main channel Will end up with extensive beaches stretching along the mouth of the river o Tides tidal currents 0 Some basic wave of land but the delta is divided into smaller islands leaving larger channels to carry the tidal flow in them irll39iumiiiiiii Drainage Basin Characteristics Size o Bigger drainage basin more water collected increased peak discharge and lag time gives us more time to prepare Vegetation o Densely forested heavily vegetated much is intercepted and re evaporated into air or drawn up by plant soil less water is collected so discharge is smaller Slopes o Steep slopes more runoff and water moves more quickly lag period is shorter peak discharge is increased Soils o Coarse sandy soil more water will infiltrate through the surface and take slower pathways which results in increase in lag period and decrease in size of flood Human Development o Reduces lag period and increases peak flood 11112010 124400 AM Aeolian Refers to wind processes Wind is a relatively weak geologic process lot less efficient in moving material and erosion Dust bowl example of wind that has impact people in history For wind to be an effective agent in shaping the land certain requirements must be met 7 r quot quot 4 ll jlllziJthirl Elllz ll ll I quot ll l Where are these requirements met Deserts MOST Deserts meet all requirements Large expanse of sand very dry low annual level of precipitation Portions where wind is most effective is where there are high levels of sand Ex Ergs The Empty Quarter Beaches Low vegetation lots of sand Agricultural Areas Typically left unvegetated for a period of the year Wind erosion can be very significant wind plays a very imp role Loess Regions Loess Fine grain material silt sized which largely originated during glacial events Large deposits in Mid West Europe China Grain is the single most important food substance Aeolian Transport of Sediments Sediment transport by wind is much like transport by running water ModesTypes of Sediment Transport Suspension Particles flow in the wind Bedload Transport Material that remains in contact with the ground during transportation Saltation Particles bouncing along the ground Creep Largest particles rolling along the bed No Solution Mode of transport like running water Dens y Air is 1000X less dense than water Erosion Layer of coarse material pebbles rocks covering the surface Start with mixture of large and fine rocks 9wind blows across surface and can only remove the dust like particles which only leaves a concentration of larger pebbles 9 surface is lowered and creates a desert pavement where wind is no longer effective Blowouts another result of deflation Compressions bowlshapedcircular or longlinear that are created where the wind has been able to deflate the surface Common in coastal areas 2 V ntifacts Angular rocks that have one or more facets flat sides that result from abrasion Yardangs Can be eroded into rock outcrops or carved into weaker unconsolidated material Streamline form created by abrasion to allow the wind to slip around the obstruction with the least amount of friction and interaction Deposition Sand dunes The best known features created by the work of the wind can come in a wide range of shapes Deposits of sand created by Aeolian transport 2 categories of dunes Fixed Dunes Mobile Dunes Dune migration tend to be relatively slow 10myear Slipface usually built up to the angle of repose Stoss slope windward slope up the dune 2 factors that control the type of sand dune Availability of sediment with more sediment can build larger dunes Winds directional variability Types of Sand Dunes 31 ill 7 in l il l 5 u girl in 23 H i ll Ll if Ll 5 ll fl 3mg i39 i 39 mam i ii ir iemniz will rein Deserts Most desert areas fall in latitudinal zones 20 40 NS very dry places Global Atmospheric Circulation aka wind patterns Primary control on geography control of deserts Regular wind pattern surface winds normally blow down toward equator Rising Air Where the wind blows into the equator and meets it is forced to rise upwards and as air rises upwards it cools and causes condensation Clouds are formed and will have lots of rain Descending Air More air coming up from the surface and it moves off to the N or S and meets with other air coming from the N or S and is forced to flow back down to the surface of the earth Air warms up and holds more moisture relative humidity decreases Tend to get clear conditions littleno cloud formation Bc this pattern is consistent we have very little rain fall Zones with descending air shift 20 40 NS Primary cause of global distribution of deserts Orographic Rain Shadows Orographic related to mountains Air blowing across pacific ocean and air begins to blow inland the air is picking up moisture across the ocean but once it hits the surface it runs into the mountains and has to rise upwards and we have the same phenomenon NW US is famous for being wet dreary place Fluvial processes are very important in shaping the landscape in a desert Ephemeral Streams Dry stream beds water only flows in occasionally Arroyos washes wadi Surprising number of people drown in these areas Playa Temporary lakes broad shallow area Ex Owens dry lake badwater Alluvial Fan Fan shapedcone shaped deposit of sediment that is created where an ephemeral stream runs out of the valley floor Will deposit material in one area for a while then shift to another area back and forth over time which creates a conefan shaped pile of debris Essentially a delta on land Common in SW Bajada coalesced alluvial fans group of alluvial fans that have grown together to form a continuous group of sediment that runs up the valley floort 11112010 124400 AM Coasts The most significant of all geomorphic environments Population Roughly 23 of worlds population live in coastal areas Economic Lots of things going on recreation fishing tourism oil and gas etc Tremendous amount of infrastructure supporting these activities Dynamic Coasts are very dynamic rapidly changing Tremendous amount of energy storms waves tidal flows Young From a geologic standpoint coasts are very young environments Further out of equilibrium which causes more change Water Zones Offshore Not part of the littoral zone Nearshore Where the littoral zone begins 10m water depth Surf Zone Move landward from the nearshore Area where waves peak up and then break crashing down Under low energy levels MS waves break right on the shore very narrow surface Swash Zone Landward most edge of the water Swash is the water that rushes up the beach every time a wave hits Land Zones Foreshore Seaward most land zone Area between high and low tide High tide foreshore covered with water Low tide foreshore is fully exposed As the tide goes up and down it moves back and forth along the foreshore BeachBerm Landward of foreshore Flat portion of the beach Backshore Landward of the beachberm Includes sand dunes cliffs Two major processes that operate in a Coastal Environment ihinii l rz in mu 5quot Tidal range Difference in elevation between the highest and lowest water level Microtidal range lt2m Mesotidal range 24m Macrotidal range gt4m Flood Period of time in which water levels are rising lquot quot if 39 l i o i y Lunar Tidal Bulge Water tends to get attracted to the place on the earth s surface that is closes to the moon which creates a lunar tidal bulge Moon and earth together are orbiting around a common center of mass as a system Bc the earth is so much bigger than the moon the common center of mass is in the crust Result of orbiting around point is second development of tidal bulge on other side of the earth 2 high tides and 2 low tides each day Prediction Lunar tidal bulges are the strongest factor to determines tides Gravity moon and sun Moon orbits around the earth on 28 day cycle As it orbits around earth tidal bulges fall Wave crest High part of the wave Wave trough Low part of the wave Wavelength Difference in height between the crest and trough Difference between 2 successive wave troughs or wave crests Height of the wave determines how much energy a wave has Higher wave more energy and more work it can do Lower wave less energy and less work it can do Wave Steepness heightlength height divided by length Influences direction of sediment movement underneath waves Low steepness push sediment on shore Steep waves push sediment off shore to cause erosion Wave speed in terms of Wave Period The waves period is the amount of time it takes for a wave to travel one wavelength Typical periods for ocean waves would range from 23 sec very low waves to as much as 25 sec very long waves Waves carry tremendous amounts of energy Power source of waves Wind solar energy and Sun solar heat Wave generation the creation of waves 3 basic factors that control the nature of the waves Wind speed Faster the wind the bigger the wave more friction Duration Longer the wind blows arger the wave Fetch Refers to the distance of open water that is available for wind to blow across When wind crosses along the water surface it creates a circle the diameter is the distance across the surface which is equivalent to the wave height As you go deeper in the water the diameter of these orbits get smaller Time it takes for water particles to go through a wave orbit is the same as the wave period Wave Base Depth is roughly 12 of wavelength bottom of the wave in shallow water Shallow depth shortens wavelength The wave is in shallow water when it begins to come in contact with the bottom of the ocean and can move sediment around ena ca idem iiimi iiiiiii il i 39 3 t l c Hl ii ALongshore Current Caused by waves approaching the shoreline at an angle angle of incidence Waves start moving sediments around creating currents Water flows parallel to the shore and if the current is strong enough it will push sediment with it Can subdivide the wave energy into 2 directions Portion of the wave energy is directed in the onshoreoffshore direction Portion of the wave energy is directed in the longshore direction Beach drift Longshore transport of sediment along the foreshore As 1 of these waves comes into coastline and it breaks and water rushes up beach the waves come in on an angle Tsunami Generated by something that displaces the surface of the ocean for a relatively large area 2 basic mechanisms that drive tsunamis Earthquakes Very large scale submarine landslides In deep water tsunamis move very fast Height is very small the wave length can be 100 km Have very little impact and can be hard to notice Wave base is extremely deep Acts like a shallow water wave Coastal Landforms Coastal Landform Classifications Material Sandy coasts will have dunes barrier islands Rocky coasts will have rocky cliffs Muddy coasts will have extensive salt marshes Dominant processes involved Primary Coasts that were formed mostly by terrestrial processes and marine processes haven t had time to reshape them yet Ria drowned river valley Delta primary process is the input of sediment from the rivers Fiord Secondary Coasts that have been significantly altered by marine processes Wavecut cliffs flat surface in front of the cliff is solid rock caused by erosion Barrier Islands strongly influenced by wave processes Coral Reef Coasts created entirely by marine corals Erosional Landforms Coastal terraces Look like a series of steps moving inland First stage is formation of wavecut cliffsPlatforms Erosion will carve a notch which over time will get larger until eventually this overlying material can t support itself and comes crashing down in forms of debris which is the beginning of the form of wavecut cliffsplatforms Carve another notch into the base of the cliff and the same process happens Change of sea level result of land uplifting or actual sea level changing which then begins to form another terrace Arches Carved into the headlands Form as a result of wave refraction focusing energy on a headland Cut notch into either side of headland and eventually merge and cut through to form a tunnel leaving an arch As the arch grows larger the bridge that connects the top will weaken and fall which creates stacks Stacks Last step in the break down or erosion of headland Isolated stumps of rocks Depositional Landforms Beaches Extremely dynamic go through cycles Type of wave determines the shore 2 types i if w39il39r Both examples of features that are created by longshore transport when waves approach shoreline at an angle and net transport is going to move along the shoreline Sp s Ridges of sand that are built by longshore transport typically at location where the orientation of the shoreline suddenly changes Tend to straighten out the overall shoreline orientation when sudden change of shoreline the spit straightens it Tombolos Ridges of sand that form bridges that connect the main coastline to some Ocean Beach Characterized by relatively high energy levels fairly big waves wider and more gently sloping beach that acts as a buffer for the wave energy Foredune Moving more landward from the beach you encounter vegetation Very salt tolerant Vegetation controls the position of this first dune If sand is being added to the island positive budget sand will be deposited on the beach making it wider and the area near the ocean will be flooded less frequently and vegetation will be extended along the beach and less salinity level and overtime you grow a new foredune This cuts off the supply of sediment to the original foredune If there are large tress and much vegetation the barrier island is very stable Bay side Can find a number of environments Bay side Beaches Quite narrow and steep very low energy environment Tidal Flats Flat tablelike deposits that extend out into the water Salt Marshes Will never find salt marshes on the ocean side bc energy levels are too high Barrier Island Rollover The landward migration of a barrier island Sediment is picked up from the ocean side of the land and is pushed over by wave activity to the landward side and whole island shifts over peat soil builds up Dune scarping Result of wave erosion Dunes get breached and sand starts to push through them Or major storm comes and wipes out large sections of dune Peat outcrop on the beach proves that there has been barrier island rollover Peat cant form on ocean side and will only form on low energy protected landward side Overwash Fan Relatively large dune system 810 ft tall Shifts island in landward direction Barrier Island Formation many theories Spit extension Barrier island forms as a result of a spit getting breached by a tidal inland Reach a point when the spit gets so long and becomes hydrodynamically inefficient Get wave setup and blast through cutting breach through spit which leaves portion of spit detached from mainland called a barrier island Drowninplace Water levels rise but shoreline isn t able to migrate fast enough to keep up so it drowns in place Biological Landforms Living organisms play many roles in coastal landform development Erosion in rocky coastlines secrete gases to form rocks create sediments through depositional environment Coral Reefs Created by living organisms corals and most of reef is actually dead Created from exoskeleton of past generations of corals which builds shell on former generations and adds to growth of reef Limited distribution which limits processes of coral organisms themselves Limited by gyres rivers and their need for warm water shallow water Most corals require quite warm water so typically only found in lowtropical latitudes mostly on the western side of the ocean basin Gyres Large circular flow that mixes hot and cold water which creates a warm current restricts coral development Corals need shallow water have to have a bottom to attach to for growth Areas that are near major rivers bc they carry huge amounts of sediments Many corals are filter feeders so they don t like water that is rich in sediment Controlslimiting factors Temps salinity light sediment supply 3 Classes of Coral Reefs classes represent the stages in coral reef development Fringing Reef 1st stage Volcanic island that has emerged from the ocean and is still actively growing Start to develop coral reefs along the shoreline Barrier Reef 2 d stage Island drifts off the hotspot Huge pile of material that is no longer growing Isostatic adjustment weight of material causes it to sink As it sinks the coral reef grows vertically Island is partially flooded and coral reef are separated from the mainland by lagoons Atoll 3rd stage Process of subsidence continues Island is now completely submerged below sea level but the corals have grown vertically which creates a ring of coral surrounding empty body of water with no land area within it Which of the following is not generated by longshore transports STACKS Human Impacts Sea Level Rise Increasing levels along the development of the coast Sea level has risen 3 of a foot in the past century For every unit up level sea level rise land will retreat about 100x in order to adjust wave conditions Will continue to rise at a faster rate over the next century Shoreline Erosion Associated with sea level rise Can occur very dramatically during storms but it also occurs along much of the US coastline Virtually all of our coastline is going through some kind of erosion More people living there with more activities so storms are more likely to 4 w ME w Chapter 13 Slopes and Mass Movements Slope curve in incline surface that represents the boundary of a landform o Steepness how quickly the elevation increases 0 Angle 0 to 90 degrees 0 Gradient Tangent riserun X 100 a percent 0 Forces I Gravitng the force of gravity I Friction 0 When one object slides across another some of the energy is lost and it makes it more difficult for the object to move 0 Particles in motion have to overcome the element the amount of friction depends on the surface of the particles I Cohesion 0 Water sticks together in droplets because of forces attracting them together 0 Why you choose wet sand for a sand castle 0 Increase slope stability and allow them to maintain steeper angles I Watercauses slope to be unstable 0 Weight force 0 Makes it less stable 0 Water controls the type of slopes of mass movement that is going on and it controls how much sediment can be moved 0 Lubricant 0 Reduces friction and allows movement 0 Makes it less stable 0 Buoyancy 0 Supports material weight 0 Reduces friction 0 System I Inputs Weathering I Outputs Transport I Inputs are caused by weathering over time the slope builds up and becomes steeper and steeper I Outputs are caused by material that gets transported off of the slope through mass movement I Develop towards Equilibrium Angle of repose o Slopes will tend to move to an equilibrium involving their steepness o The steepest angle that a given material can maintain against gravity 0 The angle at which a material can stand on its own 0 Slope elements I Waxing slope 0 Increase of the slope 0 Inputs 0 Starting from the top to waX means to increase tends to act at the source area I Free facefall face 0 Transport zone 0 Immediately below the waXing slope steepest portion of the slope I WaningDebris slope Mass Movement 0 Types Where debris collects and is taken out of the system Deposition zone Debris in between free face and waning slope where a lot of the material going to the free fall area to the waning slope Waning slope is getting less and less steep where material tends to accumulate Classified by speedamp water content I Falls avalanches O O O O I Slides 0 O O I Flows O O O O I Creep O Fastest forms of mass movement Only slowed down by friction Do not require water but it may act as a trigger In a rock fall the material completely leaves contact with the slope falling directly through the air only thing to slow it down is the friction of the air it is moving through Avalanches reach high speeds of7080 mph Difference is it retains some type of contact with the slope o Rocks bouncing down the hill with friction of land to slow down the fall 0 A little slower than a true fall because the slope is not as steep 0 Intermediate speeds and water content Material for the most part moves as a cohesive chunk moving as a unit down the hill Vegetation stays intact Involves a large amount of water like a river of mud into gravel and rock Can reach rapid speeds Materials maintain continuous contact with the ground MiXture of earth materials and water that gush down a slope Slowest movement not something that one will notice mm or cmyear Produces evidence over a large amount of time Thawing drying or cooling of the surface sediment causes it to contract with the help of gravity The combination of expansion and contraction of slope sediment is the gradual downward movement of the slope it creeps Slope Developmentln uences 0 Rock strength The stronger the rock the steeper the slope it will be able to maintain 0 Climate I Arid Very angular slow rates of development I Humid Temperature slope more weathering develops quicker 0 Process I Weathering limited How sediment moves off the slope it is being transported faster than it can be replenished Greater output 0 Slow rate ofweathering 9 parallel retreat I Transport limited 0 Rapid build up that occurs faster than mass movement 0 Inputs are slowing down over time so debris pile gets larger and larger causing a more gentle slope 0 Greater input 0 Slow rate of transport 9 debris piles up I Time Changes over time the longer the time the greater the development Parallel retreat o The slope profile stays constant over time 0 An equilibrium system Slope decline Suggests that over time slopes will get atter Slope replacement 0 We start out with sheer vertical cliff o Begins to weather and piles of debris pile up and the initiallysteep cliff gets lessened by debris 0 Cliff erodes backwards erosion accumulates Chapter 9 Water Resources Global distribution of water 0 Saline 97 0 Fresh 3 I Surface 78 0 Ice gt 99 0 lt1 lakes rivers soil atmosphere I Ground 22 0 Deep 50 o Unusable too expensive to pump up 0 Shallow 50 usable Hydrologic cycle 0 One of the major systems that shifts material and energy around the earth s surface interconnected with all of our major spheres 0 Changes in physical state ofwater movement ofwater Global budgetbalance 0 Ocean 9 40 units 9 Atmosphere over the ocean 9 40 9 atmosphere over land 9 40 9 land surface 9 runoff 9 40 9 OCEAN Reservoirs Refers to anything that stores water for a period of time 0 Storage Atmosphere ocean rivers lakes soil living organisms glaciers 0 Residence time the amount of time water spends in a specific reservoir Changes in state 0 Evaporation condensation sublimation solid to gas gas to solid Movement 0 Precipitation Vertical I Form of rain or snow 0 Runoff Horizontal I Flat sheet ofwater owing over ground surface or ow through the ground 0 Advection Horizontal movement ofwater vapor Groundwater o Aquifer a body of porous material that stores water I Confined Partially overlaid by an aquiclude I Unconfined Land surface above it is completely open 0 Aquiclude I Nonporousimpermeable rock that won t allow water to enterleave These are aquifer boundaries Saturated zone Zone filled with water Zone of aeration Zone above the saturated zone that is filled with air Water table The top of the saturated zone Recharge rate I Rate at which new water is being added to groundwater I Depends in part on the climate in the area and the nature of the aquifer 0 Rate of movement I Flows very slowly metersday week or month I Sand moves quicker than clay 0 Cone of depression I Water is being sucked out through a well faster than water can ow through an aquifer localized limit of how rapidly water can be replenished I Localized around wellhead 0 Water table drawdownGroundwater Mining I Outputs and no inputs I When the water table drops I Negative budget I Pumping water faster than it is being charged 0 Pollution I Remains in high concentration not spreading out I Is affected by the rate ofmovement in groundwater I Very difficult to correct because of slow movement 0 Saltwater intrusion I Big problem in coastal areas I Flow of groundwater to ocean when pump is slowed down salt can come in o Aquifer collapse I Pore space drained ofwater and filled with air I Destroyed porous spaces in an aquifer result of groundwater mining Chapter 14 River Systems 0 Drainage basin 0 Nestedwater sheds o The areas that supply water to one particular drainage system 0 Major US drainages 0 Pacific west of Rocky s o Gulfcentral US drain in the Gulf of Mexico 0 Atlantic east oprpalachian s o Drainage divide Area of higher elevation that separates drainage basins o Interception Stem ow drip portions will be lost through evaporation o Throughfall Fall through vegetation to the ground surface without any interruptions o Runoff I Overland ow I Run off on the surface directly to the nearest channel I Fastest pathway for precipitation to move 0 Infiltration Penetration of water down into the ground OOOO I Through ow Water that ows through the soil second fastest pathway I Groundwater Some portions provided to the river channel slowest pathway Drainage patterns 0 O O O O Dendritic I Treelike I Top right to bottom left I Consistent I Very energy efficient I Gathers stuff from an area and bringing it to a point I Allows river system to cover drainage basin with smallest channel Parallel I Top right to bottom left downhill I Consistent I Steep slopes stronger downslope trend Radial I Out from center I High elevation in middle I Tributaries falling down a mountain in all directions Trellis I Many ridges occurs in heavilyfolded topography I Stream capture 0 One tributary captured water from one valley and shifted it over to another one piracy Deranged Doesn t really seem to have a logical explanation disturbed landscape Flow in channels 0 O O 0 Water sources I Variability Flow regimes how persistent the ow ofwater is over time I Ephemeral 0 Water ows through the channel once every several years decades I Intermittent Water only ows in the channel for part of the year 0 Central California I Perennial Yearround ow 0 Mississippi river Discharge I The volume of water owing past a point in a river channel per unit of time I Measured in cubic feet per second of cubic meters per second I Q Width X Depth X Velocity Exotic streams I Natural anthropogenic Sediment transport 0 O O O O O Competence The largest grain size capable to be moved Capacity Total amount ofsediment it is capable of carrying Erosion Picking up sediments from the bed of the river Translocation Moving it to another location Deposition Putting it back down Solution I Dissolved load Suspension U l I Larger can range in size from clays to silts and finer portions of sand sized grains particles held up by the turbulence of water I Suspended load 0 Bedload Particles maintain some degree of contact with the bed I Saltation Hop along the ground in a series ofbounces I Traction Maintain continuous contact with the bed in a rolling fashion Channel types 0 Braided I Large sediment supply I Large variability in ow I Mountainous areas common to find these Multiple channels I Water ow changes season to season I Tasman River NZ 0 Meandering I Faster ow on outside I Slower ows on inside I Single channel I Less dynamic I When water ows into a curve the same amount has to ow out o Meander migration I As water goes around a curve one side travels faster causing more erosion the other side is going slower and sediment is being deposited because ofless velocity and less distance to travel 0 Point bar I Land oor slowly building up where soil is being deposited I Depositional zone on inside ofmeander curve 0 Oxbow lake Meander river cut off I False River 0 Flood plain I Formed from a meandering channel 0 Levee I Form ofprotection built by people some are natural I When water escapes over banks deposition occurs 0 Yazoo tributary I Named after Mississippi s Yazoo River I Flows along oodplain near by until they reach a levee that has a channel they can reach 0 Meander scar Only visible from above left behind by meandering channels Stream gradients Changes over time plays important role determines how much energy the river has to do work 0 Base level Bottom of drainage basin where river empty outs 0 Potential energy I Energy ofposition energy comes from objects position relative to other things 0 Kinetic energy 0 Longitudinal profile I Curve of slowly decreasing steepness down to the base level 0 Graded stream Rivers tend toward the equilibrium gradient 0 Nickpoint I Where we find waterfalls into terraces I Generates a lot of turbulence I Waterfall 0 Entrenched meanders I Colorado Plateau I Meander curves that have been cut deep down I Can be created during stream rejuvenation o Alluvial terraces Series of steps or terraces that run on either side of the river valley Deltas Depositional features created where a river enters a larger body of water ie the ocean velocity drops capacity drops and it deposits all the sediment forming the deltas o Sediment supply Deltas that are controlled by sediment 0 Wave energy Sediment inputs relatively low long beaches 0 Tidal ows I Triangle I Area dominated by multiple distributaries I Fly river I Tidal range can reach very deep 0 Delta characteristics I Found at the mouth ofa drainage basin depositional features created by rivers deposits of sediment triangular I Water velocity drops at the mouth of the river the rivers competence and capacity drops Flooding o Statisticalprediction o Recurrence interval 0 llydrograph I Chart that shows change and discharge over time o Lag time I The amount of time that it takes for the inputs rain to filter through the whole system into the river where your peak discharge occurs time between peak rain and peak ood 0 In uence of drainage basin characteristics on hydrograph I Can cut off specific areas to get water through quickly and reduce lag time Chapter 15 Aeolian Process and Deserts Requirements 0 Sediment size 0 Moisture little or none arid is ideal o Vegetation little or none Areas affected 0 Agricultural areas survival 0 Sandy coasts tourism 0 Loess areas that are undergrained by loess fine grain and sand 0 Ergs deserts Sediment transport 0 Air vs water density 0 Air is 1000X less dense than water therefore less effective at moving sediment o No solution transportin getting air Suspension Bedload o Saltation particles bouncing on surface 0 Creep particles rolling on surface 0 Erosion o De ation picking up and moving fine material I Blowout Bowlshaped compressions 0 Important in coastal zones when vegetation becomes damaged I Desert pavement lag surface 0 Course material is exposed and becomes denser o Abrasion wearing down of materials from result of sand I Ventifact atsided rocks I Yardang salted stream side 0 Deposition sand dunes predominant o Dune migration deposited on steeper slope 0 Lee slope stoss slope Slipface angle of repose o Dune controls 0 Wind direction variability o Sediment supply 0 Types of dunes o Barchans I Crescent shape I Horns point downwind I Small sediment supply I Unidirectional o Barchanoid ridge I Sinuouscrested ridge I Perpendicular to wind I Larger sediment supply I Unidirectional wind 0 Transverse dune I Crest is transverse forward I Straight crest I Larger sediment supply I Unidirectional wind 0 Parabolic dune I Crescent shape I Point upwind 0 Longitudinal linear dune I Crest parallel to wind I 2 dominant wind directions I 2 slipface orientations 0 Star dune I quotGiants of the desert I Largest sediment supply I Multiple wind directions 0 Distribution of deserts latitudinal zones 2040 degrees N amp S 0 Desert uvial processes 0 Ephemeral stream I Dry river channels only carry rain every few years 0 Washarroyowadi o Playa I Lakes filled with water that are dry at years at a time o Alluvial fan I Form in areas where mountain canyons merge on a valley oor 0 Bajada I Rants that run through valley form emerging together Chapter 16 Coastal Environments 0 Significance 0 Population 23 ofworld live around the coast 0 Transportation Trade goes on o Littoral zone area that marine sediment is actively worked by marine processes on a regular basis 0 o Tides OO O o Waves 0 O 0 Water I Offshore o Entire area before the nearshore and no sediment is being worked by marine processes on a regular basis I Nearshore o The deepest depth that waves are capable to move sediment landward to the surf zone about 10 meters 0 The bigger the wave the deeper down it can reach to stir sediments around I Surf zone Where waves break I Swash zone Broken waves rushed up by the beach and rush back down Land I Foreshore The portion of the beach that is exposed at low tide and covered at high tide I Backshore Area of the beach Causes I Gravitational attraction to the moon and the sun water accumulates on the side of the Earth that is closest to the moon Range I The difference in the elevation between the highest water elevation and the lowest water elevation Flood water levels begin to rise Ebb water levels begin to fall Spring I Highest high tide because lunar and solar tide combined I Lowest low tide I Largest tidal range I Sun and moon are on the same line I Lowest high tide because the lunar and solar tide cancel each other out I Highest low tide Smallest tidal range I Moon and sun are perpendicular 7 day process spring tide one week neap tide the neXt week spring neap monthly cycle Height Difference in elevation between the crest and the trough Length Distance between crests Period Time it takes for a wave to travel one wavelength o Steepness Same as hill if slope change in elevation over distance wave heightwavelength 0 Generation where waves come from I Fetch The distance of open water that is available for wind to blow across I Wind speed I Duration 0 Orbital motion I Path ofwater particles in the shape of a circle I As you move deeper and deeper the wave orbits get smaller I Determines the difference between offshore and nearshore o Shoaling transformation I Sequence ofwave that occur as a wave moves near shallow water I Change in height length steepness 0 Breaking 0 Wave refraction I Bending of crest different depth different speed I Energy distribution at shore 0 Big areas energy decrease 0 Small areas high energy Longshore currents ow along the shore that are generated by waves that approach the shoreline at an angle 0 Beach drift longshore currents are parallel to coastline this is why you drift parallel from shore Tsunami 0 Marine earthquakeslandslides 0 Shallow water very long low height 0 Large fault underwater on one of the plates are rapidly uplifted and then the ripples occur Primarysecondary coasts 0 Primary landforms created by terrestrial processes 0 Secondary have been substantially modified by marine processes Erosional features 0 Cliffsamp wavecut platforms I Waves cut slopes more and more 0 Terraces o ArchesampStacks Depositional features 0 Beaches I Stormfairweather profile changes I Extremely dynamic trying to find and equilibrium I Fairweather long period of swell laves o Spits Extensions of shoreline from longshore transport parallel o Tombolo s Perpendicular to shoreline a bridge as a longshore transport shadow zone 0 Barrier islands I Subenvironments I Formation Spit extension I Rollover Entire form gets pushed I Washover fan I Peat outcrop GEOG 2051 Exam 1 Review Chapter 1 Essentials ofGeography Introduction 1 Geography the study of the spatial distribution of phenomena on the earth s surface a Physical focus on the natural environment and how it works b Human focus on people and the things that people do and produce 2 Four Spheres atmosphere air hydrosphere water Biosphere living things lithosphere Earth s interior rocks soil etc 3 Five Themes a Location where things are basic building blocks of geography either in coordinates or relative to other locations Place characteristics that make that place unique relative to other places Region characteristics that locations or places hold in common Movement pathways links interconnections that tie together regions and other locations HumanEnvironment Interaction how people impact the environment sumo Methods ampTools 1 Scientific Method Equot 539quot F Fquot a World Image starting point of the scientific method our image of the real world which we gather observations and preexisting knowledge The gap in our knowledge is the problem that we try to solve Theory body of commonly accepted current knowledge what is generally accepted to be true c Hypothesis a provisional explanation of some phenomena that requires verification educational guess d Verification we try to prove our claims are false by collecting data through experiments or observations and then analyze our data Systems the concepts and ideas that make up systems theory are abstract which means they can be applied to a number of different ideas and concepts a A system can be defined as a group of objects and their attributes which are linked together by ows of matter and energy b Open Systems matter and energy can enter and leave Closed Systems energy and matter can t enter or leave a true closed system won t be able to o u erate indefinitel 39 be de u leted P P U a o a c m a P r a a a a 1 6 a lt a a P Pi L In W l 39 n Conservation of Matter and Energy matter can t be created or destroyed although they can change forms a Positive Budget Inputs gt Outputs b Negative Budget Outputs gt Inputs Equilibrium the idea ofa balanced budget Most natural systems work towards this a Static inputs outputs and storage all remain constant b Dynamic inputs outputs and storage are all constantly chan 11 over time they average out and equilibrium is maintained Lag Time the amount of time between some change in system inputs and the system it Location but intercon nected So 1 response to 7 9 0 a Latitude series of circles that run around the globe uses reference points of the center of the earth and the equator 0 degrees latitude shows north and south ranges from 090 degrees North and South Longitude meridians origin is the prime meridian which passes through Greenwich England and the center of the earth 0 degrees longitude ranges from 0180 degrees East and West 9 Map Projection the earth is round so its difficult to cut a round model of the earth and lay it down at There is always one point on the glove where a piece of paper is touching at this point there is no distortion all attributes are projected accurately The further you move away from this point of contact or standard the more distortion there will be a Cylindrical a paper is wrapped around the globe and then projected b Planar the paper is placed at on the globe c Conular ou can shrink the cone so that there are two different standard or contact lines Remote Sensing collecting information about distance and location without direct physical contact done by interpreting energy waves light and sound a Electromagnetic Radiation classified in terms ofwavelength Active Remote Sensing active systems direct a beam of energy at a surface and analyze the energy re ected back Example radar c Passive record energy radiated from a surface Example satellites Platforms the most important platforms are satellites that orbit the earth and collect information about the earth s surface a Geostationary satellite is extremely far from the earth s surface but collects a large picture of the earth from a distance b Polar Orbit rotates north to south while the earth rotates east to west so that it gathers a complete image of the earth 5 10 Geographic Information Systems GIS an organized system of different types of data Then using a computer you can search for different types of data and layter them into a map Chapter 11 The Dynamic Planet HistoryStructure of the Earth 1 539quot Planetesimal Hypothesis a massive cloud of gas and dust nebula begin to undergo a process known as nuclear fusion caused by the heat and pressure of the gasses within the massive cloud Surrounding the ball of gas the dust particles and other things oating around fell into orbit those things began to collect and gather to eventually form the planets Geologic Time Scale a Precambrian 46 billion years BP 12 billion years ago b Phaneroxic 12 billion years ago present subdivided i Quaternary 2 million years ago present 1 Pleistocene 2 million yrs ago 10000 years ago 2 lloloscene 10000 years ago Present ii This is the time period that concerns us most Dating a Relative Dating allows us to put things in order based on things relative to it Superposition the oldest rocks would be at the bottom of the formation and the youngest would be at the top of the formation b Absolute Dating gives things an exact date Dendrochronology Tree Dating we cut the tree and count the rings that are on the inside of the trunk c Radiometric Dating there are elements that are radioactive and break down over time they lose particles from the nucleus of their atoms which then changes the elements into different elements i HalfLife the time it takes for 12 of the parent isotope to decay into the daughter isotope ii Isotopes different forms of the same type of element based on the number of particles in the nucleus 4 Uniformitarianism Present is the key to the past we should interpret the past by observing earth s processes today a Gradualism the earth developed very gradually over long time periods b Catastrophism the earth s surface and its features were formed in one or more major catastrophes 5 Interior Structure of the Earth a Core the innermost layer Can be subdivided into two layers i Inner layer extremely hot and extremely dense approximately 5000 degrees Celsius or hotter composed ofmetals mostly solid iron The iron is solid because of the pressure that is created and it squeezes the liquid metal into a tight very dense ball ii Outer layer surrounds the inner layer pressure and temperature have both dropped Composed ofmetals like the inner core but pressure has relieved enough so that these metals can ow molten iii The earth s magnetic field that keeps away solar particles is generated by these metals in the core b Mantle surrounds the core subdivided into layers i Asthenosphere temperatures are much coolerthan they are in the core but they re still warm enough so that the rock and mineral that this layer is comprised ofis still in the molten state sort oflike plastic important in regards to the way the earth is shaped and formed temperatures have also cooled ii Uppermost Mantle less dense and cooler so that the material can solidify this layer oats on top of the asthenosphere c Crust has the lowest density of all of these layers made of solid rigid materials that are welded on top of the uppermost mantle i Oceanic Crust what makes up the oors of the oceans tends to be denser than the continental crust ii Continental Crust the stuff on the land d The Crust and the uppermost mantle together is known as the Lithosphere oats on asthenosphere shifts w the currents Earth Materials 1 Major Elements Oxygen approx 47 Silicon 27 a Minerals i Quartz Oxygen Silicon ii Feldspar 75 Oxygen Silicon Aluminum Calcium Sodium Potassium iii Mica Oxygen Silicon Iron Potassium Magnesium b By combining minerals together you form rocks These particular minerals form Granite the most common rock in the continental crust 2 Rock Cycle a Igneous Rocks Rocks that have formed from the cooling and solidification of magma Weathering and erosion breaks down igneous rocks down into smaller bits and pieces known as sediments These are easier to move and are often carried by water andor wind b Lithification the process of compaction and hardening of sediments to form Sedimentary Rocks c Sedimentary Rocks rocks formed by the process oflithification processes of cementation compaction and hardening of sediments d Metamorphism changes the particles of rock at the molecular level when exposed to tremendous heat and pressure carrying off or adding on atoms so that it becomes a fundamentally different sub stance metamorphic rocks 39 Usually more compact than original rocks and are harder and more resistant to weathering and erosion Igenous Rock Metamorphism happens during collisions between slabs of Earth s crust Sedimentary Rocks When sediments collect in a broad depression in Earth s crust and because of their own weight create enough pressure to transform sediments into metaphorphic rock e All rocks can undergo changes so that it turns back into magma starting the cycle over again 3 Sedimentary Rocks a Clastic weathered and fragmented rocks that are further worn in transport clast particle sediment i Sand sized particle diameter sandstonemudstone ii Silt sized particle Siltstone iii Clay sized particles ClaystoneShale iv Conglomerate a catch all rock that is made of several different sized particles and sediments that are all lithified together b Chemical Sedimentary Rocks formed from dissolved minerals transported in solution and chemically precipitated from solution ions and atoms i Example Limestone lithified calcium carbonate derived from inorganic and organic sources ii Evaporation chemical sediments from inorganic sources are deposited when water evaporates and leaves behind a residue of salts c Organic sedimentary Rocks rocks that are formed by particles of organic origins i Coal particles that are left behind from plants build together normally marine organisms ii Limestone shell sea organisms extract calcium carbonate from sea water and then it becomes a part of their exoskeleton which is left behind when the organism dies This material then undergoes lithification to form shell 4 Igneous Rocks formed through the cooling ofmolten rock a Magma Compositions i Mafic Magmas associated with oceanic crust materials usually more dense common example is basalt ii Felsic Magmas associated with continental crust materials less dense common example is granite b Location ofwhere Magma Cools also controls the rate at which the magma cools ii39 i Intrusive inside the crust usually forms rocks with a coarsegrain texture the magma will cool slowly which gives it lots of time for crystals to grow larger and larger rockis a poor conductor of heat Extrusive outside of the crust on the surface fast cooling up on the surface air is a better conductor of heat forms rocks with a finegrain texture 5 Intrusive Formations a Plutons landforms that are created when Igneous rocks build together and layer upon one another 39 All plutons are formed below the surface it isn t until the overlying material is eroded that it comes to the surface and forms landforms This is a general term for any intrusive igneous rock body regardless of size or shape b Types Badolith the largest pluton form forms many large mountain ranges such as the Sierra Nevada in California Sills smaller plutons that have formed parallel to layers of sedimentary rock horizontally eroded at table like Laccolith a type of sill that is formed by the pressure of magma pushing the surface of the sill upwards sort of like a dome iv Dike vertically eroded 6 Metamorphic Rocks a Heat any rock igneous or sedimentary can undergo metamorphism when the surface rock is subjected to high temperatures and high compressional stresses over millions of year b Contact Metamorphism low gradelow intensity metamorphic process often occurs in the area that surrounds the cooling magma chamber As heat escapes it bakes the surrounding rock which changes the rock at the molecular level c Regional Metamorphism occurs at a larger scale higher intensity metamorphic process large portions of areas that surround mountain ranges and create prairies that are actually beds of sedimentary rock Major Processes 1 Isostasy combines the principles ofbuoyancy and balance to explain the vertical movements of Earth s crust a Isostatic movements vertical movements caused by changes ofweight by loading andor unloading material on the earth s surface occurs over very long periods of time b Mountain Erosion the formation of a mountain range eventually causes the lithosphere to sink down into the asthenosphere reducing elevation The mountain is eventually weathered down and as material is unloaded elevation is increased again and the material will eventually form continental shelves that extend upon the ocean floor for miles and miles c Glacial isostasy the retreat of glacial ice unloads weight off the crust which causes the crust to ride higher 2 Subsidence 7 ii39 Chapter 12 Tectonics Earthquakes and Volcanoes Plate Tectonics 1 Plate Tectonics the basic idea is that the Earth s Lithosphere isn t a continuous skin Instead its broken up into chunks known as Lithospheric plates these plates are oating in the Asthenosphere the forces that are created when these plates move together is what forms the different landforms and landscapes we see on the Earth s surface 2 Boundaries distinguished by the different directions the plates are moving See pg 319 a Divergent Boundaries Convection Currents are created when heat causes molecules to move in a sort of circular patternThe plates are moving away from each other because of the magma that is heated underneath the plates i Also known as a sea oor spreading zone creating new oceanic crust ii On the land this can cause a rift zone rift valley b Convergent Boundary characteristic of collision zones when two plates bump into each other i Creates a subduction zone when the denser ocean oor will grind beneath the lighter continental crust ii Old crusts are recycled c Transform Boundary when the plates slide past each other in opposite directions i Lateral movements Wilson Cycle Life Cycle of an Ocean Basin A continent rifts when it breaks up creating a rift valley As spreading continues an ocean opens passive margin cools and sediments accumulate creating an ocean basin Convergence begins an oceanic plate subducts creating a volcanic chain at the active margin Terrain accretions from the sedimentary wedge welds material to the continent As two continents collide energy thickens the crust and building mountains continental conve nce The continent erodes thinning the crust beginning the cycle all over 539quot Global Supercont1nent Cycle a Cycle is approximately 400500 million years long b Continents are united into one super continent Rift valleys develop dividing the super continent Ocean Basins grow larger pushing the continents apart and creating convection zones c Eventually subduction pulls them back together d Most recent Pangaea 5 The internal heat of the Earth is an important energy source that causes the movement of these plates 6 Evidence a Wegener s Drift he found fossils of different creatures and organisms all over the world finding similar kinds of rock and elements characteristic to a particular region all over the world b Mid Ocean Ridges down the middle of each ocean basins there are huge mountain ranges convergent boundaries c Paleomagnetic Stripes a set of stripes surrounding the oceanic ridges where rocks have their magnetic fields ipped d Radiometric Dating the date of rocks is older on the outsides ofoceanic ridges i Ocean Basins lt 200 million years old ii Continental Crust gt 4 billion years old F Folding and Faulting 1 Folding a bend within a rock convergent plate boundaries compress rocks causing this deformation a Forces that impact folding 539quot i Tension tensional forces are those in which we are pulling apart forces are exerted in opposite directions So when these opposite forces are exerted on a rock the surface of the rock is attened ii Compressional Force When force is squeezed in on both sides iii Shear Force when forces act in opposite directions but offset on each other this causes lateral bending b Terms describing Folds i Anticline Ridge that is created when the rock is folded ii Synclines the valleys that are in between the ridges iii Limbs the sides ofa fold iv Dip the angle at which the limb is inclined from the at ground below V If the dips are the same on both sides of the ridge it s a symmetrical fold vi An asymmetrical fold is one in which the limb angles are different vii We re also interested in the compass orientation of the folds By knowing this we can determine the strike of the fold direction fold is oriented in viii Plunge the angle at which the fold is diving down into the ground Faulting when rocks on either side ofa fracture displace relative to the other side a crack or break in a rock a Fault Zone the areas where fractures in the rock demonstrate crustal movement b Tensional Faults two forces pull in opposite directions creating a large crack i This is known as a normal fault ii The fault scarp is the steep cliff that is created the side of the crack iii Fault Plane an imaginary twodimensional sheet like surface that fits between the crack c Reverse Thrust Fault when two compressional forces push together to create a sort of mountain like landform d StrikeSlip Lateral Transform Fault When two forces move against the strike orientation of one another similar to lateral bending two plates slipping past one another e Plate Boundaries represent the biggest kind of fault Orogenesis the creation ofmountain systems typically form along convergent plate boundaries plates are slamming into one another which generates volcanic forces a Ocean to Ocean Oceanic Plates converge the denser plate gets pushed down into the mantle where it melts creating a subduction zone The less dense components of that material gets forced upwards creating volcanic activity along the surface of the oor As more volcanoes form they begin to merge into one another eventually creating an island arc mountain system iii Common example Formation of Japan this is why they see so much volcanic activity b Ocean to Continental Oceanic plate gets pushed down its always going to be denser then the continental plate less dense gets pushed upwards Compressional forces also in uence the faulting and folding of this materialMixture ofvolcanic forces and physical mechanical forces Example Formation ofAndes c Continent to Continent two relatively low density plates get pushed against one another There s no subduction though because one plate won t get forced down so instead you will see a tremendous amount of folding and faulting Mechanical forces physical Example Formation of Himalayas h l Earthquakes 1 9 F Fquot 7 Earthquake a release of energy that moves through the ground to form seismic waves any sort of collision can form these seismic waves majority of earthquakes happen along tectonic plate boundaries Focus Focal Point where the earthquake actually occurs can be on or below the surface Epicenter the point on the surface directly above the focal point the place where energy is the most violent Elasticrebound theory the theory scientists use to explain the happenings of earthquakes a Asperities points in the fault where the rock is perfectly in line and sort ofmelded together This causes a buildup of strain Eventually that strain gives away and causes a slip which then cases an earthquake The energy that the asperity gives off once it releases and breaks apart is the energy that forms seismic waves Earthquakes usually happen in groups i Fore Shocks the smaller earthquakes that lead up to the main earthquake ii After Shocks smaller earthquakes that occur after the larger one Moment Magnitude Scale Richter Scale an objective scale values are measured measures the amount of energy released in a given earthquake a Ranges values from 010 b Logarithmic Scale each whole number goes up by a value of approximately 30 i Magnitude 2 30x larger than a magnitude 1 ii Magnitude 3 30x larger than a magnitude 2 900x larger than a magnitude 1 Mercalli Scale subjective scale based on what we feelexperience up on the surface a Northride 68 more damage highways were destroyed b Landers 74 happened in the middle of the desert very little damage Frequency how many times an earthquake occurs in a given period of time as magnitude of an earthquake increases frequency per year decreases 9 P Volcanism 1 PW Hotspots Places where unusually large amounts of heat are coming up from the mantle and through the crust this heat can escape for thousands ofyears but usually isn t enough to create a rift valley Magma Type a Mafic associated with oceanic crust and material low viscosity thinner effusive eruptions b Felsic associated with continental crust and material high viscosity thicker explosive eruptions Viscosity the strength of the intermolecular forces within a uid the stickiness of a uid Eruptions a Effusive gentle eruptions that produce enormous volumes oflava annually produce a low viscosity magma that builds up over many eruptions and long periods of time to form Basalt Gases readily escape from this magma because of the low viscosity so it pours out on the surface with few and small explosions and few pyroclastics Flood Plateau Basalt Snake Water Canyon Shield Volcano gently sloped mountain landform build from effusive eruptions that gradually rises from the surrounding landscape to a summit crater Example Mt Rainier ii39 b Explosive magma that is produced by the melting of subducted oceanic plate and other materials is thicker more viscous so it creates a blockage that cases pressure to build eventually resulting in an eruption i Composite Volcano explosively formed mountains built up in alternating layers of ash rock and lava Tend to have steep sides more conical Example Mount St Helens ii Pyroclastics fire rocks that are erupted from an explosive eruption ash lapilli bombs 5 Magma Chamber Source of the material that drives the volcanic activity 6 Conduit pipes that lead from the magma chamber to the surface of the volcano 7 Vent has a crater that is created from the explosive power blowing the material out A Calderra is a very large crater that extends over miles 8 Nueearente the heated cloud of gas and dust you see blowing down the side of the volcano at the speed ofa landside Think Pompee Continents and Topography 1 Cratons a nucleus of ancient crystalline rock on which the continent quotgrowsquot the heartland region of the continental crust Typically eroded to low elevation Continental Shield a region where a craton is exposed at the surface Terranes welded onto cratons are chunks of other foreign materials that weld onto the craton to form current continents could be from collision with other continents during global supercontinent cycle a Endogenic Process collectively describes these processes which are all powered by the same energy source Earth s internal heat b Exogenic Process energy source is external solar energy weathering etc these processes tend to wear down landforms and landscapes though they can be constructive ex beaches Topography the undulating form of Earth s surface including its relief the lay of the land Relief the vertical elevation differences in the landscape Topographic Regions and Orders of Relief a Plains low relief very at buried under blankets of sediment that has been eroded off of other categories b High Tablelands c Hills and Low Tablelands intermediate levels of relief associated with distribution of shields exposed craton very old materials subjected to long periods ofweathering once high elevations worn down d Mountains highest relief associated with collisional plate boundaries e Widely Spaced Mountains f Depressions 7 Landscape Scales a 1St Order largest covering billions of square kilometers changes the slowest takes longest amount of time to significantly alter features of this scale driven by endogenic processes Ex continents and ocean basins b 2 101 order occupies a significant portion of continent of ocean basin very long amounts of time are needed to alter features endogenic processes Ex Rocky Mountains c 3ml order smaller shorter amounts of time to alter them endogenic processes with some exogenic process Ex Blue Ridge Mountains within Appalachians 9 0quot Fquot d 4 order smallest special scale up to this point few hundred to 10s square kilometers less time to alter features exogenic processes driven by solar energy Ex individual mountains within range e 5th order Ex individual river valley on a mountain 6th order even smaller beach ripples etc H Chapter 13 Weathering Karst Landscapes and Mass Movements Weathering 1 Weathering the break down of materials into smaller pieces a PhysicalWeathering processes require mechanical forces pushing pulling expanding shrinking etc Bonds are being broken by the application ofa physical mechanical force b Chemical Weathering processes that attack natural elements at the molecular level Operates in a temporal time sequence 2 Temporal Time Sequence a Bedrock Parent rock that gets broken down b Regolith the same material as the parent rock only slightly broken down c Soil smaller bits of the regolith mixed with bits of organic material 3 Parent Material Controls a Iointing how many crocks run through the rock important because it adds surface area b Hardness c Solubility 4 Climatic Controls a Precipitation affects the rate of the weathering process b Temperature affects the type of weathering process c Hydrology the study of water in the environment what we re referring to however is the movement of water through the environment determines how much ofa given surface is exposed to water i Slope small exposure ii Flat surface longer exposure iii Depression longest exposure like a bowl causes rapid weathering d Topography e Vegetation can both inhibit weathering as well as enhance it 5 Physical Weathering Processes a Frost Action when water freezes its volume expands This expansion creates a powerful mechanical force known as frost action Repeated freezing expanding and thawing contracting of water can break rocks apart b Root Wedging roots grow larger over time and enlarges cracks eventually breaking and shattering c Crystallization water deposited gets in cracks of rock and then leaves behind salt deposits when evaporated which grows over time getting pushed further and further apart until the material shatters Exfoliation pressurerelease spalling As overlaying layers of rock are weathered away and eroded tremendous weight is removed off of the top layer of granite and pressure within the deep burial is relieved However the structure of the rock that once had equivalent forces pushing out to balance it is gone overlaying rock but the inside rock is still expanding which causes cracks and peeling 6 Chemical Processes a Oxidation rust P b Hydrolysis when minerals chemically react with water a decomposition process that produces different compounds c Dissolution of Carbonates when a mineral dissolves into a solution i Water vapor readily dissolves carbon dioxide therefore precipitation contains carbonic acid from the air This acid is strong enough to dissolve many minerals particularly limestone ii Chemical weathering involving dissolution of carbonates dominates entire landscapes composed oflimestone karst Topography Karst Top ograp by 1 9 F 0quot Sinkholes circular depressions caused by the weathering of limestone in landscapes a Solution sinkholes formed by carbonation b Collapse sinkholes formed if a solution sinkhole collapses through the roof of an underground cavern Karst Valley an elongated depression of sinkholes caused by continuing solution and collapse Tower Karst Haystack Karst weathering can leave isolated blocks of resistant limestone standing causes a remarkable build up in the shape ofa Tower Disappearing Streams a stream will run on the surface and then disappear into a sink hole beneath surface run underground for a while and then merge back up onto the surface All forms of karst topography are underlined with systems of caverns a Dripstones form as water containing dissolved minerals slowly drips from the cave ceiling Calcium carbonate precipitates out of the evaporating solution literally one molecular layer at a time and accumulates at a point below on the cave oor Stalacites depositional features that grow from the ceiling Stalagmites build up from the oor Column a stalactite and stalagmite that has connected Drip Curtain horizontally formed like an actual curtain QEDPP Final 0 About 40 cumulative questions 0 30 new questions Biosphere Biogeography o Focuses on the spatial arrangement of living organisms Understanding spatial variability in the biosphere leads to ecology Ecology 0 Study of the living organisms and how they interact with each other 0 The basic fundamental idea is an ecosystem o Ecosystem 0 Set of livingbiotic organisms and their nonlivingabiotic surroundings that are linked together by ows of matter and energy 0 The entire world is one complex ecosystem o Biomes o The largest scale of ecosystem that we use 0 Regions internally homogenous in the biosphere 0 Living organisms within a biome are linked together by ows of matter and energy Energy Flows in the Ecosystem 0 Sun powers the ecosystem through photosynthesis o lst trophic level 0 through photosynthesis some organisms of plants are able to x their own energy by absorbing solar energy from the sun to break apart particles of carbon dioxide and water and form their own molecules that contain higher levels of energy that can be released by plants at a later time 0 Plants are primary producers o In all terrestrial ecosystems plants represent lSt trophic level 0 Gross Primary Productivity GPP o The total amount of energy that plants can x in ecosystem 0 End up using most of the energy that they x themselves through respiration o GPP Respiration NPP net primary productivity 0 What is left for the other organisms in the ecosystem o Forests have the highest productivity level then grasslands then streams with the lowest 0 2 major trends both linked to climate I Temperature D Colder environments are least productive D Global distribution of biomes follows the global distribution of climate I Moisture D For any given temperature zone the wetter side of the environment is more productive 7 where you nd forest o 239 1 trophic level Primary Consumers o Herbivores 7 organisms that get energy by consuming plants and extracting the energy that is stored in the plants 0 3rd trophic level secondary consumers o Camivores 7 meat eaters get their energy by consuming herbivores and getting the plant energy second hand 0 4th trophic level 7tertiary consumers 0 Top cainivores 7 carnivores that prey on other carnivores o All of the trophic levels are linked together by the decomposers 0 Ex Fungi bacteria 0 Get energy supply from the left over material 0 Break down waste products from each trophic level 0 Food Chain 0 Energy moves from level to level following a pathway but there are usually multiple connections between the levels 0 Food web is much better arranged for an ecosystem 7 so if one pathway is destroyed there are still other pathways 0 Structure of ecosystem is created that you rarely nd 4 or 5 trophic levels 0 At each trophic level some energy is used up 0 10 rule 0 Only about 10 of energy xed at a given trophic level is available to be passed on to the next level the rest is used in respiration 0 As you go higher on the food web there is less energy available 0 Organisms have to cover a large territory in order to get enough energy to survive Flows of Matter in the Ecosystem 0 Things are more complex with matter 0 Matter enters and leave at all of the trophic levels 0 Nutrients 0 Various substances that organisms need to survive o Maeronutrients I Nutrients we need in large quantities I Carbon Oxygen Hydrogen Nitrogen Phosphorus Potassium o Micronutrients I Nutrients we need in small quantities but are still essential I Zinc Boron Copper 0 Biogeochemical Cycles 0 O O O O Collected pathways that any nutrient follows Every nutrient has its own biogeochemical cycle Found in reservoirs in biosphere hydrosphere lithosphere etc People can alter the fundamental operation of these cycles on regional or global basis Ex Carbon Cycle I One of the primary pathways that carbon follows is through breathing I Animals breathe out C02 and plants take it in I We can alter this cycle by burning fossil fuels Nitrogen Cycle I Atmospheric end is a very important reservoir it accounts for about 70 of the gas in the atmosphere in nitrogen I Nitrogen is in chemical form N2 that is chemically inert and doesn t react very well with anything else therefore our body cant use it I Most living organisms need nitrogen in a different chemical form nitrogen formed with oxygen molecules to form nitrates which our bodies are able to use I Lightning I 1 form of how nitrogen gets converted to a form we can use I as a bolt moves through atmosphere it super heats air that surrounds its pathway which causes many chemical reactions to create nitrates or nitrites I Nitrifying bacteria I Live mostly in the soil U More important process that fixes nitrogen in useable fonn I Cultural entrophication D One of the common problems associated with nitrogen D Results from action of people and over feeding D Huge in ux of plant feed in water bodies and result is the primary produces often algae grow like crazy D Algae die and the decomposers bacteria take over which creates a bacterial bloom D Bacteria get oxygen by extracting it from water so result is dissolved oxygen levels decrease D Ifoxygen levels drop low enough you will get dead sh zone 0 Bioaccumulation o Refers to the tendency of some substances to accumulate in living organisms 0 Especially fat soluble substances ex Vitamin A 0 Large doses of Vitamin A over a period of time can make you very sick 0 Biomagni cation 0 Can increase our exposure to toxic material 0 Tendency for concentrations to increase and we move up the food chain Operation of Ecosystems 0 Population 0 refers to the members of individual species ex blue whale pop Community 0 refers to a number of species that share some portion of the environment Habitat 0 refers to the nonlivingabiotic surroundings that an organism requires to fulfill its life cycle Niche o The function or role an organism plays in an ecosystem 0 You can only have one organism occupying a certain niche Competitive Exclusion Principle 0 If 2 organisms are trying to occupy the same niche then they are in competition with each other and one will out do the other and drive it out Mutualism o Symbiotic relationship where both organisms benefit Par asitism o Parasitic relationship where only one organism bene ts 542010 33600 PM 542010 33600 PM
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