Geography 3B Lecture and Section Notes
Geography 3B Lecture and Section Notes
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How do landforms change What modifies the surface of the earth How do these systems interact with each other Geography 0 Writing the earth 0 Processes that happen on or near the earth39s surface Systematic Geography 0 Modeling and predicting spacial phenomena Physical and Human Geography Scale in geography 0 Earth realms O Lithosphere atmosphere hydrosphere biosphere 0 Life is found on a shallow level 0 Scale 0 Global scales 0 Continental scale 0 Regional scale 0 Local and individual scale 0 Time scale and cycles Systems Theory 0 Interdisciplinary field of science that studies the systems in nature and society 0 Systems have an energy source structure resource flows and cycles feedbacks and functions 0 Systems have resistance resiliency stability and equilibrium 0 Open system 0 Inputs and outputs 0 Not much cylcing O ie a car 0 Ecosystem model 0 Inputs energy nutrients water Endogenic vs Exogenic Processes o Exogenic processes are set in motion by energy from outside the earth 0 The sun is the source of exogenic processes such as weathering o Endogenic processes are set in motion from within the earth 0 The radioactive thermal energy at the earths core sets in motion molten lava and volcanoes Geography and Global Change 0 The fields of human and physical geography have tremendous implications for 0 Global climate change 0 The carbon cycle 0 Biodiversity 0 PoHu on Concepts tools and technologies in geography o Pictoral models of reality 0 T andO maps Power of Maps 0 Use of symbols to represent meaning 0 Facilitate perception of spatial relationships 0 Highlight necessary information Representing the Earth 0 How do we represent the earth 0 Points latitude and longitude o A graticule 0 Why does it matter 0 How do you go from a spheroid to a 2D plane 0 What implications can this have 0 Some landmasses can be made to appear larger than others by how the map is projected o 3 classes of projections o Panarproject globe on a tangent plane 0 Conicproject to a cone 0 Cyindricaproject to a cylinder 0 Mercator projection o Greenland looks bigger than Africa 0 Not true 0 Ga Peters projection o More accurate size o Equivalent projection o Preserve area 0 Conformal projections o Preserve angles 0 Topographic projection 0 Shows elevation depth 0 Temperature projection o Dot distribution map used for cropland projection o Choropleth map used for transit coisions o Cartogram used for population 0 Why the seasons and biomes 0 Uneven heating of the Earth 0 Tilt of the axis 0 HadleyFerrel Model 0 Wind patterns Ocean currents 0 Orographic precipitation 0 Air rises to cross mountains o Rising air expands and cools 0 At dew point temp it condenses and forms clouds 0 Continued condensation produces precipitation Remote Sensing 0 Collection of info about Earth39s surface through aerial or satellite imagery models EDA simplified representation of a portion of reality expressed in conceptual graphic or mathematical form 0 Models convey a set of interrelated theories about structures and processes of a system of interest to the world 0 Expresses the parts and their causal implications GIS Geographical Info System ltZgtToos for performing spatial analysis ltZgtData is contained within layers 0 Layers can be placed on top of one another and can be hidden 0 Google Maps CED Traffic layer Z3 Earth layer 0 Google Earth CED Roads layer Z3 Boundaries layer 0 Layers Terrain models Network Utilities Lotsownership Zoningdistricts Base mapping 0 Examples populations exposed to flood risk True Physical Measurements ltZgtGeodetic measurements ltZgtPhysica measurements of earth systems ltZgtExampes water quality sampling vegetative sampling carbon dating soil texture analysis Key concepts ltZEgtOpen system external inputs cause a changereaction o exogenic ltZgtCosed system processes are self contained and nothing is gained or lost 0 Volcanoes geothermal energy 0 Endogenic ltZgtFeedback loops 0 Systems can have or feedbacks in other words the system can actually influence itself 0 Global warming 0 All of these processes can be classified into spheres Geology and Landforms ltZgtLandforms are determined by the complex interactions of endogenic and exogenic processes 0 Endogenic geological processes CED Igneous and metamorphic rock formation CED Crustal deformation 0 Modified by exogenic geomorphic processes CED Weathering for example Terrestrial Landsurface ltZgtTopography o The undulations and configurations including relief that gives the earth its texture o Represented gt maps and globes DEMs Raster and Vector data Relief ltZgtReative relief elevation variations on terrestrial landsurface Z33 orders of relief 0 1st tectonic plates oceanic or continental plates 0 2nd plate collision or divergence 0 3rd created by erosion and deposition ltZgtFat means low relief Hypsometry ltZEgtCharacterization of the elevation relative to ocean level Key Elements ltZgtLatitude where something is relative to the equator and poles ltZgtLongitude where something is relative to a designated meridian Need to describe things in relation to time Geologic Time ltZgtOccurs over millennia ltZgtTime periods 0 Eons CED Eras CED Periods CED Epochs Current Epoch ltZgtHoocene epoch 0 Beginning of the retreat of glaciation ltZEgtCurrenty debated if we are in a new epoch o The anthropocene or the epoch of man Relative vs Absolute Time ltZEgtReative what happens in what order ltZgtFirst place second place third place in a race for example ltZEgtAbsoute time if actual times are given Why important ltZgtSometimes we don39t know exact times Uniformitarianism ltZgtPrincipe that the exact processes that are happening today have happened through geologic time 0 Linear connection between events is allowed bc of this rule CED Implications for biology etc Ocean is stable from weathering processes Earth is layered like an onion ltZgtnner core ltZEgtOuter core ltZEgtLower mantle ltZgtUpper mantle Crust ltZgtOceanic thin high density ltZgtContinenta thick less dense Mantle ltZEgtTo 2900 km ltZgtTwo layers brittle crust lithosphere soft partially melted asthenosphere 0 Key pt lithosphere forms plates that float on magma Liquid Outer Core ltZgtLiquid nickeliron source of magnetism Solid Inner Core L 9CgBLU39 g A95 L39H 5lopfq h L crVrq 3qLm num 3 EJasm 0 39 P nluC0m95eCL mc3nijfwn J from k Pt 4 law 5 rEqJ39nj qlre Fe cs I w in gang 9 r c rmj lt Lrm1Amuuemampn T M 0z T 0z p 418 1E rH 5 fig mam H g Gang 15Gyquot iZt3 L ii 395 5 r W E Etltmq fne1 5quot L a A3 as J at M gt PUtr A 39 T 9 lgJ LIm Vj W i i i art EriJ H L C911 ms 39fIUrpJ1Erg DUWX Tm9Uquot ma p j A y p8 M f4 1 cA me q5Vl1 norjpJ3Ere 1 on p lt l91 E5 moemnJ39S Bqr mf crms p gtMfah We grmq 0 r2H9 iEjL9 L 0 P7 A J ee quot39f ntquot1399T131 girth rat S ig vuf 1 Pm grn 1 i39e 39 W Aw ma rm ma anl Lava Wan ml T5 an M b U A TT TT TT AV p Van TT mzlqmnrfnli if clam T T N lfmggrm g Lgt1 A 4 Z3 7 can mens9mna Lo3 8 T Tnoc lns Crgtq5c1li xc5 1 up I T T HE T T T HT wLIquotUK1 Magma gnu V i fmcCt55Vg coalma me dyragm rrvn 4quotM qS395mL 5 T 9 a r TTrras LI 0w r CB0quot j T u nL ws v U ampU rgn oug rodn51 fv rqre egtJHws vri Fa LIJ Gwrip c d f L1m rz en o an mlugweioogg Ofr tijmq J cIn4 9 i392z T A n A 31 39lmamp n L P7L G L gtltquot3f P2 EIHI 101795 9 Whec nu vnsT1gte nouk r wcAaraAe sTT qflfi gmon W mTT5 fgW lH L0 m 1 M T WT P T N 0 g L 9 3 fwubn T T ra5 5 T1T lr399V3 f3 1Cr KC quot P qTS 1L fal39 on 4 Ig e U5 nf 39Ck P TT V H 7 gquotAc Lgmyfqr M5 FJILC p F WIT 5TT quota AA J1 3 J51 K T x MNyea pamb quot 3 3 339 n Mae Lecture 4 Notes April 7 Recap 2 types of metamorphism o Regional metamorphism o Contact metamorphism 0 Touching intrusive magma o Gneiss and granite are metamorphic rocks Earthquakes and Volcanism o Movement of plates cause Crustal deformation 0 Folding and faulting 0 Responses to stress 0 Unique features Crustal Deformation o Gets deformed due to stresses it endures O Tension lt gt normal fault Compression gt lt reverse fault Shear gt strike sip fault lt Responses to Stress o Strain is how rocks respond to stress 0 Folding 0 Faulting 0 A rock folds or faults based on the amt of stress and the comp of the rock 0 A rock is said to be c Brittle when it breaks easily o Ductile when it is more pliable Folding Anticline o An anticline is a type of fold where the ridge is the peak of the folding Folding Syncline o A type of fold where the trough occurs Practical Importance o In the petroleum Industry 0 Oil and gas accumulate in anticlines 0 Helpful with water resource management Special Cases o Residual synclinal ridge 0 Different weathering qualities o Overturned anticline 0 Thrust fault o Stress causes the strata to give and the rock thrusts out Faulting o Expression of a strain on rocks as a fracture 0 Point where plates move and separate to move in different directions 0 When the energy released via faulting is felt this is an earthquake o Fault plane 0 The surface along which 2 sides of a fault move Types of Faults o Normal or tension fault 0 Due to tension o Thrust or reverse fault 0 Due to compression 0 Very low angle reverse fault o Thrust fault o Strike slip or lateral fault 0 Along plate boundaries o Transform fault 0 Right or left lateral depending on the plate movement Transform Fault o Two plates diverge in the ocean and the line is not uniform Horst and Graben o Horst is an uplifted block o Graben is a downshifted block Terranes o Fragments of another continent that have collided and become part of the current continent Orogenesis o Refers to how mountains are created o Orogeny is a mountain building episode o Orogens are major chains of faulted and folded mountains o Orogeny can occur due to migrating terranes accretion at continental margins or the intrusion of magma forming plutons o Net result of all this activity is the thickening of crust o Types of oregenies 0 Oceanic platecontinental plate collision o Often characterized by the intrusion of magma and the capturing of Terranes o Trenches along the subduction zone o These collisions can produce either simple volcanic islands or more complex chains Oceans are primarily basatic 0 Continental platecontinental plate collision o Rarely results in volcanic activity o Can create earthquakes through thrust faulting Rainshadow effect can be seen from satellite images green forest on one side of a mountain range vs dry areas on the other side Lecture 5 Notes April 9 Earthquakes o Stress from plate motion builds up along the plate edges which results in strain When the strain is overcome the result tis an earthquake o The force is recorded through the world Key terms o Focus 0 Origin within the Earth at which the seismic waves originate o Epicenter 0 The origin on the Earths surface which is directly above the focus o Foreshock 0 An earthquake the precedes the main earthquake o Aftershock 0 Earthquake that follows the main earthquake 0 Usually less powerful Can be equal in power Intensity and Magnitude o 2 scales 0 Quantitative 0 Qualitative 0 Qualitative measures damage and perceived intensity o Mercalli scale o Goes from I to XII 0 Quantitative scale o Richter scale 0 Exponentially based meaning that for every numeric increase is an order of magnitude bigger o 12 is 10X in difference 0 Moment magnitude scale which measures not only amplitude but also directional movement Nature of Faulting o Elastic rebound theory 0 Theory describing the basic mechanics of how a fault breaks 0 The points where there are areas of high strain are called asperites these are what break and cause the fault to slide o If they are not the main points of tension they can result in foreshocks Energy Transfer o Waves move through rock proportional to Modulus stiffness and inversely proportional to Density related to temp and pressure o Four types of waves 0 2 types of body waves p waves and swave o P waves longitudinally polarized o Compressionrarifaction o can move through fluids o Travel faster than 8kmsec o Swaves transversely polarized o Involve updown or shearing tension o Cannot move through fluids o Slower than pwaves 4kmsec 0 2 types of surface waves love wave Rayleigh wave o Love waves o Moves ground from side to side in a horizontal plane but at right angles to the direction of propagation o Horizontal shaking is particularly damaging to structures o Rayleigh waves o Move vertically and horizontally o Propagate in a vertical plane pointed in the direction the waves are travelling 0 Waves can interact o Need 3 seismographs to locate epicenter 0 The reflectionrefraction of waves makes data at one seismograph to be skewed o Can obtain info from earthquakes or explosions onin earth including those caused by man 0 This is how we determined the Russians had the atomic bomb and more recently North Korea Earth Science o Structure of earth derivable from different types of waves 0 Time to travel 0 Reflection 0 Refractions o This is how we know the outer core is molten 0 Swaves go around the outer core 0 P waves go through the outer core Earthquake Prediction and Planning o Very hard to do bc of variables o You can make risk assessments based on freq of past earthquakes 0 Paeo seismoogy 0 Observe phenomena that occur before an earthquake o Dilitancy 0 Monitoring rocks for a change in volume as a response to strain 0 Measured by tiltmeters 0 Radon gas release monitored by wells 0 Some places use lidar laser ranging to track movement An aside New Madrid o Sand blows were common throughout the area and can still be seen from the air in cultivated fields o Weak spot theory o Other theories 0 End of glaciation and the isostatic lift reactivated the faults 0 Pressure experienced by the moving NA plate strains this area Volcanism o What is volcanism o Building of the crust o Types of volcanic activity o Anything relating to volcanoes or volcanic activity as a result of moving magma o A volcano refers to the end of a vent or pipe that rises to the crust o Not always volcanoes o Hot springs geysers Lecture 6 Notes April 11 Locations and Types of Volcanic Activity o Volcanic activity occurs in 3 settings 0 Along subduction zones 0 Along sea foor spreading and continental rifts 0 At hot spots where plumes of magma rise through the crust o Volcanoes may behave in several different ways but 2 primary factors influence the type of eruption 0 Magmas chemistry which is related to its source ie mafic vs felsic 0 Magma39s viscosity or how easily it flows 0 Mafic means much quicker flow o The process 0 New crust is formed by volcanic processes o A rift can open on the seafloor or continent o Midatlantic ridge easy african rift o A hotspot can be present o Hawaii Iceland o Lava magma that rises to the surface 0 Flowing basaltic lava has two forms o A39a rough and jagged lava that forms from slow moving lava whose skin cracks open as it flows o Pahoehoe forms from more fluid lava movement and has a 39ropy39 texture Key Terms o Ash less than 2mm in diameter o Lapii a particle size less than 32mm in diameter o Scoria volcanic slag the junk that forms as gases escape from magma or lava o Pumice similar to scoria but its density is less than 1 which allows it to float on water o Aerial bombs explosively ejected blobs of lava o Nuee Ardente a type of pyroclastic flow that glows as it moves away from the volcano o Pyrocastics also known as tephra very fine pulverized rocks and gases which are ejected during eruption o Pyroclastic fows N uee Ardente 0 A pyroclastic flow can blwo down the side of volcano 0 It will obliterate everything in sight 0 Travel extremely fast Volcanic Elements o Cinder cone formed by the expulsion of cinders pyroclastic material called scoria in the same manner as a volcano but no actual lava is ejected They are often much smaller than volcanoes reaching at most around 1500ft o Caldera a large basin shaped depression it forms after the magma chamber of a volcano collapses Effusive Eruptions o These are gentle eruptions which means not as violent Produce large quantities of flowing lava 0 50 less silica 0 Gasses escape due to low viscosity o Produce relatively few pyroclasts o Form shield volcanoes o Lava flows from main vent and side fissures o Form distict volcanic cones which are gently sloping form the surrounding landscape to the crater 0 This type of volcano is called a shield volcano o In a rift valley where you may have an extremely large fissure flood basalts also called plateau basalts may occur ExplosiveViolent Eruptions o 5075 silica o Very viscous and sticky o Magma tends to congeal and cause blockages which causes a buildup of pressure when this blockage breaks it causes a sudden release which results in an explosive eruption Composite Volcanoes o Result from explosive eruptions from other volcanoes 0 Also called stratovolcanoes 0 Called composite bc as the cone forms they are layered with ash lava and pyroclastic debns Plinian Eruptions o Marked by huge columns of ash and gas venting into the stratosphere o Often eject a large amount of pumice o Can be accompanied by pyroclastic flows o Chamber may collapse resulting in a caldera Lecture 7 Notes Denuda on o This is the process that wears away and rearranges landforms Terrestrial denudation involves 0 Weathering 0 Deformation 0 Eroding Differential weathering 0 Concept that explains why certain features appear on the landscape 0 In essence certain rocks are more resistant to weathering than others Landforms and Change 0 On one hand you have endogenic process of crustal formation orogenesis o Initial landscapes 0 Exogenic process of weathering o Sequential landscapes Dynamic Equilibrium Approach to Landforms Landscapes are open systems created by endogenic processes and affected by exogenic processes Uplift of mountain ranges creates potential energy These weather patterns drive the hydrologic cycle gt mechanical energy Interaction of the atmosphere formation of water oxidation etc and crust gt chemical energy Bc these landforms are constantly changing we can say that they are dynamic o Generation o Weathering 0 Results in a state of equilibrium as each force will work against the other o Geomorphic Threshold 0 Point at which energy overcomes resistance against movement 0 Patterns emerge over time o Equilibrium stability the system fluctuates around some average o A destabilizing event o A period of adjustment 0 The sizescope of the movement determines how long it will take to readjust o Development of a new and condition of equilibrium stability OOOOO o Slopes 0 When weathered material is loosened it is susceptible to erosion and transportation In order for this material to move downslope it must overcome friction inertia and cohesion A major factor of whether this material has the potential energy to move is slope When we are talking about slopes in physical geography we are referring to specially hill slopes Hill slopes are defined as being curved inclined surfaces that rom the boundaries of landforms o Have a waxing slope a slope that increases as you move from near the top o A free face a cliff formed by more resistant rock strata o Debris slope slope that forms from the accumulation of weathered material o Peculiarities of Debris Slopes 0 In humid climates debris slopes tend to be rather steep as water gradually transports the debris away 0 In arid climates debris slopes tend to have much accumulation and are gently sloping o This is called a waning slope as the slope is very low o This feature is called a pediment OOOO o Weathering 0 Processes that break down rock at and just below the surface 0 Occurs in 2 principle ways many times together 0 Key to note that weathering is no c the process of transport 0 Mechanical o Physical process that physically deforms the rock 0 Chemical o Minerals within rock are changed and broken down o Regolith 0 Material that forms after weathering andor erosion 0 The broken up material 0 Can be small or quite large grain of sand to a boulder o Bedrock 0 Parent rock that forms from which regolith originates o Resulting regolith will then share some of the physical properties of the parent rock like color etc 0 The resultant sediment combines with other weathered material to form parent material from which soil evolves o Factors influencing weathering 0 Rock composition and structure o Whether the rock is hard or soft soluble or insoluble o The amt ofjointing or the cracks that form in the rock These joints create more surface area which allows more chemicalphysical weathering 0 Climate o Amt of precip o Temp 0 Subsurface water o Position of the water table pt where water is located underground and water movement within soil and rock structures 0 Slope orientation o Geographic orientation of a slope NSEW affects amt of sunlight moisture and wind it receives o Slopes facing away from the sun tend to be cooler and moist 0 Vegetation o Can protect from rain o Produce adds organic acids from material that decays which can weather rock chemically o Roots can spread into cracks and over time will force cracks open as pressure builds This leads o greater surface area for other weathering processes o Physical Weathering 0 Rock is broken and disintegrated without any chemical alteration o Also called mechanical weathering 0 We describe 3 types of physical weathering o Frost action o Crystallization o Pressurerelease jointing Lecture 8 Notes Frost Action o What happens during the freezethaw cycle 0 Sometimes referred to as freezethaw action 0 When water freezes its volume can expand by up to 9 0 The expansion can eventually exceed the rocks tensile strength and a crack can become larger or the rock may break into smaller pieces o How it happens 0 A rock must have joints 0 During wet and cold periods water can enter these cracks and freeze o Frost wedging 0 This natural process was a convenient way for peoples across the globe to quarry rock by drilling holes and filling them with water 0 Water enters cracks gt freezes as temp drops expands against walls of rock gt cracks are enlarged Salt Weathering o Caused by salt crystals o Minerals that were dissolved in the water are left behind and these form salt crystals Pressure release jointing o Pressure release jointing occurs in plutons that have been revealed c As pressure from the weight of the overlying regolith is released pressure release joints form o Exfoliation 0 These joints eventually result in the rock 39peeing39 away in layers 0 These can form dome or archlike structures Chemical Weathering o This process deforms and breaks down rocks based on chemical changes 0 Many times this can be seen on old stonework tombstones etc Spheroidal Weathering o Spheroidal weathering is a type of chemical weathering c As water breaks down the minerals in a rock it begins to develop rounded edges which eventually causes it to look like a sphere o The resultant shape can sometimes look like exfoliation in physical weathering but the rocks Hydration o Hydration is when water combines with the mineral molecule o In some minerals the effect of water combination can be an expansion which then can break the rock down through a wedging type of action o A cycle of hydration can lead to granular disintegration which increases the surface area available for more weathering What is Gypsum used for o Gypsum board is used as finish for ceilingswalls and is known as drywall or plasterboard o Fertilizer and soil conditioner o A tofu coagulant source of dietary calcium o Adding hardness to water for home brewing o Portland cement component used to prevent flash setting of concrete o Helps makes mead o In foot creams shampoos Hydrolysis o Used to describe reaction of minerals with water which produces different compounds o Usually results in the production of clay and other various compounds o Eventually this will cause the interlocking crystal network to break down 0 This is called granular disintegration Oxidation o Refers to the process of oxygen interacting with certain metallic elements to form oxides o Rusting Dissolution of Carbonates o Many compounds can be contained in water because it is a solvent o H20 CO2 to make carbonic acid o Carbonic acid helps dissolve materials within rocks 0 Carbonization 0 Weathers materials that have Ca Mg K Na Karst Topography o Form where there is an abundance of limestone o Characterized by landscapes poor surface drainage and welldeveloped underground channels o Occur bc of the chemical weathering process Formation of Karst Topography o Limestone must be gt80 CaCO3 o Complex patterns ofjoints are needed for water to form subsurface crystals 0 An aerated zone must exist between the surface and water table o Vegetation cover o Climate for optimum condition for Karst landscapes Sinkholes o Circular depressions 0 Sometimes called dolines o A collapse sinkhole occurs where an underground cavern collapses and the material above falls down o A solution sinkhole is characterized by a slow subsidence and results in the pockmarked landscape o 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g QMg OJ 750 rczfwaQ x A 39 mfye quotquot 3amp3 w0 41 Qmo mnmme mAL r f39 quotYdICarA ms 39 I 1rlA gampf9 qn unbnrl95 u39op39 ap p80pquotlqLan cq LLampUQ r5M9 Gr It517 quotcquot DE F7 C T sqkswqvl in 3 wag I14 171013quot In AL 522 0 93 ltgtrquotH Ewe Irrr3ch an Pg T W N56 rv3s2k quot 0ltrt 5 04na e cer L e 2 IS 539q11YE19jgc1 He 50 s U mgut A on 5 u rzQt IA A A A p 01 M01 L we 2 r a P55 4 7 39a39 Lecture 10 Water budget and Water Resources 0 How do you ensure a steady supply Groundwater resources 0 Groundwater is an important part of the hydrologic process Groundwater profile and movement 0 Groundwater begins as surplus water that percolates downwards o It moves through the zone of aeration 0 Soil and rock are less than saturated some pores contain air 0 Eventually water reaches zone of saturation o Pores are completely filled with water Aquifers and aquicludes 0 An aquifer 0 An aquiclude or an aquitard o Bounds of an aquifer o Groundwater that may be held in an aquifer depends on the porosity of the rock 0 The flow of water through an aquifer depends on the permeability of the rock Aquifers wells and springs o A confined aquifer 0 An unconfined aquifer o Aquifer recharge area 0 What happens in each case 0 Confined and unconfined aquifers also have different pressure characteristics 0 Pressure builds Stream flows 0 Groundwater can also impact streamflow o Effluent conditions 0 Lots of precipitation 0 Water from around stream enters the stream 0 Influent conditions 0 Water leaves the stream into surrounding landscape Overuse of groundwater 0 When water is pumped through a well in an unconfined aquifer it may experience drawdown 0 Well will go dry Overpumping 0 Can lead to what is called groundwater mining 0 When the net draw of all pumping exceed the rate of recharge 0 Common in West Midwest Mississippi Valley Florida and Eastern Washington 0 Most overdrawn is the High Plains Aquifer Collapsing aquifer o On the surface this can be visible as land subsidence cracked foundations and changed drainage patterns Collapsed aquifers and coastal pumping Pollution of groundwater 0 When surface water is polluted groundwater will inevitably be contaminated bc it is recharged from surface water supplies Can come from 0 Industrial 0 Septic tanks 0 Seepage from hazardous waste disposal sites 0 Industrial toxic waste 0 Mechanized agriculture 0 Urban solid waste Pollution can be point source 0 35 of pollution comes from point sources 0 65 from nonpoint sources Fluvial Processes o Stream related processes 0 Concepts 0 Discharge 0 Volume of water between two points 0 insolation and gravity 0 External energy that drives weather patterns 0 fluvial erosion o The eroded sediment in the stream can be transported or deposited o Transported material is either rolled carried or dissolved by water in the stream 0 Deposited material is what is deposited by the stream Baselevel 0 Level below which a stream cannot erode its valley 0 Ultimate base level 0 ocean 0 Local base level o Lake 0 Dam Lecture 11 Base levels Drainage Basins o Sheetflow or overload flow is water that initially flows downslope 0 Interlude 0 Land between flows 0 Rills o Beginnings of a river Continental Divides o What divides a continents drainage flows Internal Drainage 0 Areas of drainage that don39t go to ocean Drainage density and patterns o Drainage density 0 Total area related to amount of stream activity 0 Drainage frequency 0 More branches of streams means higher freq Special Features of Fluvial Systems 0 Capture o Elbow capture 0 Where two streams connect 0 Stream piracy 0 Another stream captured by one stream 0 Rio Grande 7 most common stream patterns 0 Dendritic o Trellis 0 Radial 0 Parallel Dendriticmost recognizable tree and most efficient Treisforms in folded topography 0 Results from folded mountains Radiawhen water flows from a central point or dome o Volcano for example Paraefrom very steep slopes o Newly formedforming mountain ranges Rectangle and Annular o Rectanguardue to faulted and jointed landscapes 0 Fault lines and fault line boundaries 0 Annuarproduced by structural domes with the rock strata guiding stream courses 0 Richat Dome Deranged Drainage 0 Form on disrupted surface landlords 0 No clear geometry and are often marked by lakes 0 No pattern Superimposed streamsdefy land structure 0 Streams that keep its path as land is uplifted Stream discharge 0 Determined by how wide and deep the channel is as well as the velocity of the flow 0 Flow will generally increase as you move downstream as more water is added via various tributaries 0 When flow increases it will weather more of the landscape and carry more material 0 When a dam is built it stops the material and leaves sediment deposits in a reservoir 0 Stops migratory routes and sediment downstream for reproductive egg locations Exotic Streams 0 These are stream whose headwaters are in tropical or wet region and flows through an arid region Stream Erosion and Transportation 0 A streams turbulence and abrasion help to carve and erode the landscapes in which it flows 0 Hydraulic action is the work of flowing water alone 0 Abrasionscraping action 0 Where would each process be the strongest 0 Hydraulic action and abrasion maxes out at the beginning or near a waterfall or steep slope Competence and Capacity 0 Competence is ability of stream to move particles of a specific size 0 Function of velocity 0 Capacity happens in 4 transport processes 0 Solution 0 Dissolved load in a stream 0 This can be minerals like limestone or salts 0 Suspension 0 Fine grained bits of rock 0 Held aloft due to velocity and not deposited until stream hits zero velocity 0 Saltation 0 Along bed of a stream bed load 0 Similar to traction but it knocks other things loose that wouldn39t have otherwise moved 0 Traction 0 Along bed of a streambed load 0 Aggradation 0 If load exceeds capacity it will build up sediment along its course 0 Results in a braided stream 0 Tons of sediment slow stream Flow and Funnel Characteristics 0 Greatest velocities are near surface and center 0 Where slope is gradual stream forms a snakelike form 0 Called a meandering stream 0 Cutbank 0 Point bar 0 A meander may fill in and form an ox bow lake Lecture 12 May 5th Eolian Processes Anything oriented towards wind Ability of wend to transport material is small compared to ice and water bc of low density Grain size of classic materials is important in Eolian processes The principal wind erosional process is called deflation 0 Deflation 0 Abrasion 0 Equivalent of sandblasting Desert Pavement 0 Cobblestone like appearance that appears on wind swept landscapes 0 Or Forms by being blown away or by Deposition 0 Small stones embedded in other stones 0 Water displaces small particles downward Blowout depressions O Basins that form as wind blown material is carried away Abrasion 0 Rocks that have undergone abrasion appear pitted fluted or polished O Creates a distinct shape that forms due to the prevailing wind conditions 0 Ventifacts 0 On a larger scale entire rock formations can be sculpted o Yardang Atmospheric wind can transport very fine material such as volcanic debris fire soot and smoke within days Only very fine particles are transported long distances because they are lifted Saltation 0 How particles of sand are moved 0 Moved via aerodynamic lift elastic bounce and impact 0 On impact these particles can knock other particles into the air Eolian Depositional Landforms 0 The smallest features shaped by individual saltating grains of sand are ripples o Formed transversely 0 Only 10 of desert environments are covered by sand 0 Other 90 is desert pavement and or ice Dunes 0 In the 10 of deserts that are formed by sand are dunes 0 An extensive area of dunes is called an Erg Desert or Sand Sea Dune movement and forms 0 Dune fields whether along the coasts or in arid regions tend to migrate in the direction of effective sand transporting winds 0 A large storm or strong seasonal winds moves dune sands 0 When saltating grains hit patches o Dune key terms 0 When sand height rises above 1 Ft characteristic dune features form 0 Slip face 0 On the side where the wind will hit above and sand will slip down a face 0 Windward side 0 Faces the wind o Leeward side 0 Includes slip face 0 Sedimentary rock formed from dunes o Mechanics of slip face 0 All dunes have an angle of repose or the steepest angle at which the dune is stable 0 As a dune builds up with new material it forms an avalanching slope 0 Classes of dunes 0 Crescentic dunes o Barchan o Barchanoid Ridge 0 Last pair 0 Parabolic 0 Transverse Lecture 13 May 7th Uneardunes 0 Only one type within tis class 0 Longitudinal 0 Star dunes 0 3 or more arms that radiate out from a central mound o Other types of dunes 0 Reversing o transverse 0 Dome dune o Mounds 0 Sometimes vegetation at the top What else forms besides dunes o Loess deposits are formed from fine weathered sediment and are quite thick Deserts 0 Dry climates form about 26 of Earth39s land surface 0 They can be on small islands interior plains and mountainous areas Desert climates o The spatial distribution of deserts is dependent on high pressure cells rain shadow and location 0 Receive a lot of insolation or solar energy Desert Fluvial Processes o Eolian processes are most active in arid climates but running water is the most significant erosion Desert streams are described by type of flow 0 Perennial o Fed all year round 0 Ephemeral o Lasts a short time 0 Intermittent o Comes and goes What characteristics define desert fluvial processes What would we expect to see Other unique features can form in arid climates 0 Playa 0 Salt o Dry lake 0 Alluvial fans 0 Delta in a desert 0 Bajada a series of coalescing alluvial fans along a mountain front Deserts are unique 0 Biomes are diverse and specialized 0 Animals develop accordingly Desert fauna 0 The desert spadefoot 0 Just need sand to burrow o 12 stomach fills of food per year Deserts are region specific 0 Differ by region 0 More specialized plants and animals 0 In central Asia deserts are barren and devoid of life 0 Deserts can be mid latitude cold deserts Lecture 14 May 9th Deserts are region specific They differ by region In the US we have more specialized plants and animals In central Asia they are barren Deserts can be mid latitude cold deserts 40 of the worlds population lives 100km or less from a coastline Coastal System Components Solar energy Atmospheric winds Climatic regimes Nature of coastal rocks 0 Human activities Coastal Environmental o Littoral zone 0 From high tide to areas completely submerged 0 Landward O Seaward o Shoreline 0 Coast is portion of land from high tide to the first landform change mtns o Sea eve is officially mean sea level 0 Tidal levels every hour and averaging them over time Changes in Sea Level 0 Changes bc of natural and human processes 0 Glacierice 0 Reservoirsdams 0 Changes can be spatial Tides o Happen twice daily 0 Vary worldwide 0 Created by gravity of moon and sun 0 Moons pull is bigger o This pull creates bulges Types of Tides o Ebb Tide 0 Low tide 0 Flood tides 0 High tide 0 Difference between the two is called tidal range Spring Tides 0 When the sun and moon are in alignment 0 Greater tidal range 0 Its called a spring tide because it springs forth Neap Tides 0 When moon and sun offset 0 Narrow tidal range Practical Importance of tides o Tides with waves are a big weathering force 0 We can harness tidal energy VVaves o friction between air and water 0 Undulations up and down that you can feel 0 Waves tend to travel in groups and these are called wave trains 0 Waves originate in storm systems 0 Regular patterns are called swells Lecture 15 May 12th Wave phenomenon o What happens when waves interact with other waves or along the coast 0 If out of phase they will counteract 0 Rip current Wave refraction o In general wave action tends to straighten a coastline 0 Caused by wave refraction 0 Has to do with friction and water depth 0 Energy becomes focused Nearshore Processes o If they come at an odd angle they will create currents parallel to the coast 0 Longshore current littoral current 0 Beach drift 0 Interaction process Tsunamis o Caused by underwater movement of land 0 These can form landslides underwater to the movement of the plate 0 Huge amt of energy in one giant wave Coastal system outputs 0 There two main outputs that occur from coastal processes 0 Erosional 0 Depositional Erosional Processes o Erosional coasts tend to be rugged high relief and tectonically active 0 As waves undercut a bank along the coast that will form sea cliffs 0 Del Playa Erosional Landforms o Other coastal landlords 0 Sea caves 0 Sea arches 0 Sea stacks Depositional Pro Estes and Landlords 0 Found along areas of gentle relief where sediments and many sources are available Coastal Depositional Features 0 Barrier spit 0 Bay barrierbay mouth bar 0 Lagoon 0 Tom bolo Beaches o A beach is defined as a place where sediment is in motion deposited by waves and currents o A shingle beach is a beach devoid of pebbles and cobbles Maintaining Beaches o Humans may wish to disrupt the natural processes at work in beach formation Ways to do so 0 We can use hard structures to take advantage 0 Groin 0 Jetty 0 Breakwater GEOG 3B Lecture May 12 Wave phenomenon o What happens when waves interact with other waves or along the coast 0 If out of phase they will counteract 0 Rip current Wave refraction o In general wave action tends to straighten a coastline O Caused by wave refraction 0 Has to do with friction and water depth 0 Energy becomes focused Nearshore Processes o If they come at an odd angle they will create currents parallel to the coast 0 Longshore current littoral current 0 Beach drift 0 Interaction process Tsunamis o Caused by underwater movement of land 0 These can form landslides underwater to the movement of the plate 0 Huge amt of energy in one giant wave Coastal system outputs 0 There two main outputs that occur from coastal processes 0 Erosional 0 Depositional Erosional Processes o Erosional coasts tend to be rugged high relief and tectonically active 0 As waves undercut a bank along the coast that will form sea cliffs 0 Del Playa Erosional Landforms o Other coastal landlords 0 Sea caves 0 Sea arches 0 Sea stacks Depositional Pro Estes and Landlords 0 Found along areas of gentle relief where sediments and many sources are available Coastal Depositional Features 0 Barrier spit 0 Bay barrierbay mouth bar 0 Lagoon 0 Tom bolo Beaches o A beach is defined as a place where sediment is in motion deposited by waves and currents o A shingle beach is a beach devoid of pebbles and cobbles Maintaining Beaches o Humans may wish to disrupt the natural processes at work in beach formation Ways to do so 0 We can use hard structures to take advantage 0 Groin 0 Jetty 0 Breakwater Lecture Notes May 21 Erotional landforms post glatiation o A tarn 0 Patermoster lakes 0 A hanging valley 0 U shaped valley going into larger u shaped valley 0 Bridalveil Falls Depositional Landforms o Glacial drift 0 Sorted 0 Unsorted 0 Engrained 0 Till o Stratified drift Glacial Erratic Moraine 0 Lateral moraine o Medial moraine 0 Terminal moraine 0 End moraine Ground Moraine Compound Valley Glacier 0 When 2 glaciers come together 0 One or more medial moraines Continental Glaciation 0 Different from alpine glaciation 0 Features Till plain 0 Behind end moraine 0 Coarse till 0 Low and rolling relief 0 Deranged drainage patterns Outwash plain Esker o Sinuous narrow ridge of course sand and gravel Kettle 0 Depression in the ground that can be very deep Kame 0 Small hills or knobs composed of poorly sorted sands and gravels Lecture Notes May 28 Erotional landforms post glatiation o A tarn 0 Patermoster lakes 0 A hanging valley 0 U shaped valley going into larger u shaped valley 0 Bridalveil Falls Depositional Landforms o Glacial drift 0 Sorted 0 Unsorted 0 Engrained 0 Till o Stratified drift Glacial Erratic Moraine 0 Lateral moraine Medial moraine Terminal moraine 0 End moraine Ground Moraine Compound Valley Glacier 0 When 2 glaciers come together 0 One or more medial moraines Continental Glaciation 0 Different from alpine glaciation 0 Features Till plain 0 Behind end moraine 0 Coarse till 0 Low and rolling relief 0 Deranged drainage patterns Outwash plain Esker o Sinuous narrow ridge of course sand and gravel Kettle 0 Depression in the ground that can be very deep Kame 0 Small hills or knobs composed of poorly sorted sands and gravels Lecture Notes May 30 Soil horizon composition 0 Current research 0 The AEand B horizons are designated as the solum Nuances to Composition 0 Soil scientists may also apply a subset of classification categories to describe soil properties Soil color 0 Soil color can tell us a lot about soil Soil texture o Refers to the different particles within and the relative proportions of them Soil structure 0 Physical arrangement of particles within a soil 0 Fine medium and course 0 Rounded peds will be best for plant growth Soil consistency 0 Resistance to breaking and manipulation under varying moisture conditions 0 Level of cementation is another criteria Soil porosity 0 Controls mvmt of water within Soil moisture 0 Important for plant growth Soil chemistry 0 Involves air and water 0 Soil colloids Soil acidity and alkalinity o Acidic and basic soils 0 Acid rain 0 Most crops can39t grow below a soil pH of 6 Soil management 0 Natural factors 0 Climate 0 Biomes 0 Topography 0 Human factors 0 Can be both positive and negative Soil classification 0 The US standard is most used Entisols o Undeveloped soils Histosols 0 Large accumulation of organic matter Andisols 0 Form in areas of high volcanic activity Incep sol
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