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KEY TERMS FOR RIVERS Vocabulary for Notes use wherever there is a divide sized errace urbidity Stream RIVERS Learning Outcymes L Objectives To Successfully be Able to Explain 1 The concept and importance of a watershed 2 The processes of stream erosion transportation and deposition 3 The origin and characteristics of river landforms Misconceptions 908994P N 509080 Only the Nile River ows north Stream velocity decreases as one approaches base level ocean or lake Tomados will not strike between two rivers Groundwater ows in underground rivers Rivers and groundwater are separate Excluding the oceans there is more river water than groundwater Water from natural sp1ings is safe to drink All rivers empty into lakes seas or oceans Did you Know 1 The Chicago River is colored green on St Patrick s Day 2 The Chicago River s ow was reversed in 1900 for sanitation reasons Along the Detroit River is one of the very few places where you look south into Canada from the lower 48 states A river horse is a hippopotamus and that a river jack is an unpleasantlooking snake the African puff adder The Congo River is the longest river that ows generally westward The MissouIiMississippi is the longest river owing generally southward The Yangtze is the longest eastward owing river The Nile is the world s longest northward owing river Saudi Arabia has no natural rivers Tying it all together Climate determines the size and discharge of rivers but some rivers are termed exotic not because of their sinuous curves but because exotic rivers like the Nile River are able to maintain ow through arid regions because it originates in rainy regions The bedrock or regolith upon which rivers ow determines the form the river takes across the landscape Differences in bedrock resistance or the presence of faults will channel rivers along fairly predictable paths Where little difference exists in bedrock rivers will establish a dendritic birds foot pattern Rivers are the most important agent of landform development greater than the erosion and deposition produced by wind glaciers waves or mass wasting Even in the desert the occasional rainfall on unprotected slopes produce signi cant landform development Rivers are an important part of the biosphere supplying food providing an avenue for transportation serving as a source of potable water as a source of cooling water for industry and as a means to disperse waste and sediment eroded from the surrounding watershed L bBJECTIVE 1 Concept of a watershed an area of land where surface water and groundwater drain to a common point depending on the scale watersheds can range in size from a few acres to thousands of square miles Watersheds can and do often cross u county state and national boundaries Image httpwwwsoqueorgAbout20the20Soquewatershed20picsmallerGIF Y READ NO FURTHER In the space below write a short paragraph highlighting the implications of watersheds crossing county state and national boundaries a Think of a watershed as a type of topographic funnel all surface and groundwater within the watershed is channeled toward a lower point in the watershed eventually reaching the 1 lowest level to which a stream can erode whether it be a pond river lake sea or ocean E Each watershed or drainage basin is separated topographically from adjacent watersheds by a high point which could be a ridge hill or mountain Formation Many watersheds are formed by tectonic or volcanic processes that deform the Earth s crust through folding faulting or down warping Watersheds can also result from differential erosion by wind water or ice The structure and strength of the underlying rocks in uence the where erosion occurs with valleys typically consisting of less resistant rock and hills consisting of more erosionresistant rocks The Concept of all life forms within the watershed are linked by dependence on the same source of surface or groundwater Pollution in one part of the watershed can impact water quality in another part of the 39 J Sources of pollution are indeed varied pollutants settle out fairly quickly and may only impact water quality a short distance from the discharge point r quot andr quot in solution can be carried for hundreds of miles from their discharge point contaminating the water supply of city residents that had nothing to do with the original source of pollution OBJECTIVE 2 The processes of stream erosion transponation and deposition The form of a river or stream is determined in part by slope discharge and underlying bedrock In the space below supply your best guess how climate slope discharge the amount of water passing a certain point per second and underlying bedrock would affect the form of a river As you have outlined river form will be determined by the factors discussed above The tools allowing these factors to shape a river are erosion transport and deposition A Stream Erosion grinding of the river bed due to particle friction Solution rock and sediment become dissolved within the water column 0 the force or weight of the water striking the river bed results in erosion Hydraulic force results in a type of plucking that can pry loose weak rock and sediment B Stream Transport click on Fig 1014 Modes of Sediment Transport 800K sediment in contact with the bed carried downstream by stream ow the downstream bouncing motion of sediment in which sediments are dislodged from the stream bed suspended for a short distance and then fall back to the stream bed Sediment impact will often dislodge other sediments beginning the process over again Rolling Rock or sediment that rotates across the surface of the river bed At all times the body is in contact with the river bed dissolved sediment held within the water column Suspension visible sediment carried within the water column Excessive amounts of suspended sediment results in increased water 39 39 or Turbidity decreases light penetration reduces photosynthesis buries spawning beds an allows contaminants to be transported on suspended sediment Stream Deposition the deposition of sediment by streams when the quantity of material carried by the stream is greater than the competence or ability of the stream to carry its current load of sediment any sediment deposited by streams Discharge and Deposition the the discharge the the ability to ca1ry material through suspension and through bedload When discharge declines aggradation will occur Discharge and Sediment Size the the discharge the greater the ability or competence of the stream to carry sediment sizes Boulders will be moved when discharge is greatest only clay sized particles will be moved when E discharge is low Access the following video on a graded stream to better understand the graded stream concept The relationship between ow erosion and deposition is depicted for a steep and gentle stream profile The graded stream concept is also applied for a ood scenario OBJECTIVE 3 The origin and characteristics of river landforms Alluvium Bedrock Scarp Floodplain PcmtBav Yazoo Stream lncipient am Natuval Levee Chanrwl Culolf Images httpwwwuwspedugeocoursesgeog391torivimages5Clandformgif a plain next to a river and prone to ooding Bluff a steep prominent slope originating from river erosion a at na1row stretch of ground often having a bluff face facing the river Terraces often represent former oodplains that were left stranded at a higher position when the river down cut to a lower level Click on Figs 1027 1043 1045 Flood Plain and Stream Terrace 1400K Natural Levee An elevated bank of alluvium bordering a river The bank is deposited when the river leaves behind much of its load during ooding a stream having a pattern of snake like turns View th animation to view how an actual river has meandered over a half century the outer portion of a river meander usually steep which is continually undergoing erosion a gentlesloped wedgeshaped deposit of alluvium on the inner portion of a meander Thalweg The deepest portion of the strearn s channel produced by faster moving erosive stream ow l Meander Neck a narrow isthmus of land separating two adjacent meanders In the space below draw a meander and where to navigate a canoe a Oxbow Lake Formation A portion of a meander now a lake which has been cut off from the original river channel Oxbow lakes became isolated from the original channel as a river cuts through a meander neck to shorten its course blocking off the old channel The new river channel then migrates away from the lake Eventually oxbow lakes silt up to form wetlands and nally meander scars quotquot Based on this animation of oxbow lake formation draw a two to four step 5 3 diagram illustrating how oxbow lakes form Return to for Earth Science and 39 Instruction KEY TERMS FOR WEATHER AND FRONTS Vocabulary for Notes use wherever there is a 01 a in a table Scale masses Plains region pressure leader emperature ornado Alley ater droplets aterspouts FRONTS AND WEATHER 2007 httpwn nrenhall n 139 Summary This chapter discusses storms and temporary disturbances in the atmosphere We will focus on air masses types locations movements fronts warm cold other midlatitiude cyclones characteristics movements life cycles midlatitude anticyclones nonstorms and tropical disturbances tropical cyclones or storms known as hurricanes in the United States Focus will also be on smaller storms such as thunderstorms and tomadoesImage Prentice Hall Liccts6l7632l92wave cvclone fig tasa rshadipg cited 19 June 20067 Objectives To Successfully be Able to Explain l 2 3 4 How and where air masses form and how they are classi ed The general characteristics of cold warm stationary and occluded fronts The steps necessary for thunderstorm formation The sequence of events resulting in cloudground lightning and lightning safety procedures 5 How and where tornadoes form and why tornadoes are so destructive Misconceptions 1 Lightning never strikes the same place twice therefore lightning rods are only good one 99 9 time Open all windows when atornado is approaching Michigan s UP is always cooler in the summer The origin of heat lightning is different from regular lightning Thunder occurs without lightning The origin of heat lightning is different from regular lightning Cold fronts always bring cold weather warm fronts always bring warm weather Did you Know 1 For a storm to exhibit blizzard characteristics visibility needs to be reduced to 14 mile or less due to blowing drifting andor falling snow Winds need to be 35 mph 58 kmh or greater 2 The largest recorded hailstone weighed 225 pounds or 102 kilograms 3 A large mature thunderstorm can produce up to 4 inches 100 mm of rain per hour 4 An intense low pressure cell in 1921 destroyed 8x the number of Douglas fir trees as the Mt St Helens eruption The average midlatitude cyclone dumps 200 trillion lbs of water Lightning is hotter than the sun39s surface About 100 fatalities occur annually in the Us due to lightning You can t have thunder without lightning and you can t have lightning without rain and hail Therefore you need water and ice to make fire in the sky lightning 40000 thunderstorms occur around the world each day Most strike in the equatorial region It takes the sound of thunder 5 seconds per mile 3 seconds per kilometer to travel from the location of a strike to the observer This delay can be used to estimate the distance of an approaching storm 11 The deadliest tornado on record is the Tri State Tornado which killed 695 people on March 18 1925 as it passed through Missouri Illinois and Indiana 12 More people die from oods than any other natural disaster 13 Silver coins and maggots have quotrainedquot from severe storms 14 Eighty percent of all lightning fatalities are male 15 Codell Kansas was struck by three tornadoes in consecutive years 191618 and all on the same date May 20th 16 Half of all people who die in ash oods die in their cars 9 89 0 O r Tying it all together Last session we learned concepts associated with atmospheric moisture like evaporation condensation humidity dew point fog clouds and various forms of precipitation from sleet to hail Moisture content of a parcel of air is an important feature in the classification of air masses Fronts whether cold warm stationary or occluded have predictable moisture characteristics depending on location relative to the front In some places rainfall and nimbostratus or cumulonimubus clouds are to be expected In other locations it s still dry with only high clouds portending rain or snow Evaporation and condensation are central to the formation of thunderstorms Without the release of latent heat cumulonimbus clouds could not spawn tomados lightning and thunder h n OBJECTIVE 1 How and where air masses form and how they are classi ed Air Mass an extensive body of air with similar characteristics an extensive body on the earth usually plains or oceans with uniform temperature moisture and pressure characteristics Classification of Air Masses Important to the US Using your textbook fill in the table below l uquotn u39u nvr H7119 Cool dry clear conditions for cP Michigan temperatures in the seventies or high sixties Cool moist cloudy conditions for Michigan temperatures in the seventies or high sixties Not mP common as these air masses become modi ed by the large land mass crossed from the source region in the North Paci c Warmer cloudy moist for mT Michigan temperatures in the thirties or low forties Warm dry conditions for Michigan temperatures in the thirties or low forties Not CT common as these air masses become modi ed by the large land mass crossed from the source region in the American Southwest OBJECTIVE 2 The general characteristics of cold warm stationary and occluded fronts What is a front A between to contrasting How are fronts symbolized Use your textbook In the space below draw the proper symbolization for the four types of fronts Assuming the top of the page is north draw a cold front so it is advancing to the east the warm front so that it is the north and an occluded front advancing toward the northeast advancing from the south the stationary front so that cooler air is located to Are cold fronts always cold Cold front is a relative term When is the last time you experienced below zero temperatures when a cold front passes after reworks on the fourth of July When is the last time you broke out the bathing suits after a warm front passes after Super Bowl Sunday Even slight differences in temperature and moisture conditions can herald the passage of a front Thus if the high temperature on Monday is 800 and the high temperature on Tuesday is 76 a cold front could have gone through town Sometimes the only real indication that a cold front has come through is a change in humidity and a shift in wind direction Cold fronts Cold air replaces warm air at surface In the space below a cold front in the cross section Associated air mass and Cold front characteristics i Before Passing While Passing After Passing Winds southsouthwest gusty shifting westnorthwest Temperature warm sudden drop steadily dropping Pressure falling steadily minimum Sharp rise rising steadily increasing cirrostratus stratocumulus altostatus then stratus or nimbostratus or Clouds cumulonimbus and cumulus cumulonimbus in summer heavy rains sometimes showers then Precipitation short period of showers with hail thunder and clearing 11ghtn1ng f 11 d b d t 39 Visibility fair to poor in haze Poor 0 owe y goo excep m 1mprov1ng showers Dew Point high remains steady sharp drop lowering Warm fronts Advancing warmer air rises above cooler denser air Associated air mass and Warm front characteristics Before PaSSing While Passing Winds southsoutheast variable southsouthwest coolcold slow warming steady rise warmer then Temperature steady usuall fallin levelin off sli ht rise Pressure y g g g followed by fall in this order cirrostratus stratustype clearing with altostratus nimbostratus scattered Clouds stratus Stratocumulus and fog occasionally occasionally cumulonimbus in cumulonimbus in summer the summer lighttomoderate rain drizzle or none usually none Precipitation snow sometimes light sleet or drizzle rain or showers oor oor but fair in haze V1s1b111ty p p 1mproV1ng Dew Point steady rise steady rise then steady Based on your textbook readings and the tables above predict what you would nd in regard to Wind Direction Relative Humidity Dewpoint Temperature and Pressure for a city that has just experienced the passage of a cold and warm front Also predict the same weather parameters for a city about to experience the passage of a warm and cold front To access a current weather make go to SURFACE WEATHER MAP FROM INTELLICAST Don t know the name of cities Use Google Maps Pressure Pressure Wind Direction RelativeHumidity Dewpoint Temperature b m City Predl Actual Predl Actual Predl Actual Predl Actual Predl Actual A Cold front has passed through B Cold front will be passing through shortly C A warm front has passed through D A warm front will be passing through shortly A stationa front results when there is little or no along the front between contrasting air masses Occluded fronts can bring long periods of similar weather including large amounts of precipitation Occluded Front the cold front has overtaken the warm front forcing warm air aloft OBJECTIVE 3 The steps necessary for thunderstorm formation Two major classes of thunderstorms air mass thunderstorms and thunderstorms Thunderstorms need air and a source in order to form I Airmass or ordinary thunderstorms generally form in warm weather are usually shortlived and rarely produce strong winds and large hail Three stages for air mass thunderstorms Cumulus stage the release of latent heat and updrafts Mature stage strong updrafts continue but now there are cool to cold produced by evaporational cooling and descending rain that drags the colder air to the surface Cloud heights ofup to 50000 ft Dissipating stage downdraft dominated Why many times it actually feels more rather than less oppressive after a thunderstorm evaporation of falling rain has increased the point 11 Severe thunderstorms form in unstable moist air and where the wind speed increases with often in the vicinity of a jet stream Upper air winds cause the storm to tilt allowing updrafts to move over downdrafts Severe storms also form when a convective cap is breached Severe thunderstorms are capable of producing 1 large hail having at least 34 inch diameter 2 strong surface winds with gusts of 50 knots or more 3 strongf J A called 4 tornadoes Gust front precedes hail and heavy rain 10 0 LHail Cold gravity current Here is how a gust front forms Image Kelvin K Droegemeier httpkelvinoueduMETR202603metr2603lecture2htm Note the Shelf and roll clouds above the gust front Where warm moist air is forced above the advancing cold air The mechanism for uplift is similar to that ofa cold front Tmsm39nm nquot 39 39 4 4211 4 wind shear 0n the ground severe damage can occur wim Speeds ofup to 150 mph While quot m m a c 1 39 39 Lhewestem onmcnvmwh 1 39 39 J safety procedures A L A a h Inn 39 quotquot 39 39 m n um m r down I 39 39 H 39 mecloudmd E u n another cloud connect and ZAP you have lightning 1 39 39 39 39 quot 39 39 On39gin Lighter charged ice particles and water droplets gather at the top of the cloud heavier negatively charged ice particles and water droplets gather at the of the cloud 2 Opposite charges attracta region on the ground builds a positive charge 3 Electric potential builds the insulating properties of air break down and a near invisible stroke of electrons called a leaves the cloud and approaches the ground 4 A positive charge leaves the ground usually along objects 5 The positive and negative discharges meet there is a ow of electrons to the ground and then a visible stroke of positive ions along the path created by the stepped leader Thunder is the sound that results from the heated air along the channel of the lightning stroke Contrary to what a once popular song may have said remember Thunder only happens when it s lightning Heat Lightning because the visible lightening stroke is below the horizon or obscured from view only the wide diffuse illumination produced by the lightening is visible Heat lightning usually originates many miles from where it is observed too far too hear thunder Scattering of the light often results in a yellow or orange appearance of this type of lightening Minimizing Risk IF 0U T DO0RSAvoid water Avoid the high ground Avoid open spaces Avoid all metal objects including electric wires fences machinery motors power tools etc Unsafe places include underneath canopies small picnic or rain shelters or near trees Where possible find shelter in a substantial building or in a fully enclosed metal vehicle such as a car truck or a van with the windows completely shut If lightning is striking nearby when you are outside you should A Crouch down Put feet together Place hands over ears to minimize hearing damage from thunder B Avoid proximity minimum of 15 ft to other people 3 IF INDOORS Avoid water Stay away from doors and windows Do not use the telephone Take of head sets Turn off unplug and stay away from appliances computers power tools amp TV sets Lightning may strike exterior electric and phone lines inducing shocks to inside equipment Quoted directly from National Lightning Safety Institute 2007 Personal Lightning Safety Tips Ia39 httpWWW quot r H mm nlsi nls lst html accessed 3 Julv 2007 OBJECTIVE 5 How and where tornadoes form and why tornadoes are so destructive A tornado is a rapidly rotating column of air around an area of intense that extends from the base of a cumulonimbus cloud The Visible funnel cloud of a tornado is J of and dust The funnel cloud is classi ed as a tornado when a funnel cloud descends toward the surface as air rushes into its low pressure core cools at successively lower levels beneath the parent thunderstorm The majority of tornadoes have wind of less than 125 knots diameters of less than 600 meters and occur most frequently in the Greatest Distribution along including Texas Oklahoma Kansas Nebraska the Dakotas Missouri Illinois and Indiana On the of all the tornadoes experienced in the United States annually the average is over 800 the majority fall into the weak category F0 and F1 and only a few reach the Violent category F4 and F5 It is the Violent tornadoes that account for the majority of tomadorelated deaths Timing is usually the most frequent month for tornadoes during the day most occur in the late and early evening Tornadoes are least likely to occur at Origin 1 At the surface an open wave cyclone exists with cold dry air behind the cold front and warm humid air behind the warm front 2 At about 5000 ft relatively warm moist air is streaming from the south 3 At about 10000ft cold dry air is moving cold dry air is moving northeast 4 Upper air divergence draws humid surface air into unstable air aloft 5 Wind direction and speed change rapidly with height updrafts begin to rotate cyclonically 6 Spinning air increases in speed and rises drawing in air from all sides this spinning vortex will extend to the cloud base and eventually to the ground Minimizing Risk Doppler radar has helped scientists gain a great deal of information about tomado generating thunderstorms Write the de nition difference between a Tornado warning vs Tornado Watch When a tornado approaches don t bother opening windows seek shelter immediately that form over water are usually smaller than tornadoes have weaker winds than tornadoes and tend to form with developing cumulus clouds KEY TERMS FOR ATMOSPHERIC PRESSURE AND WIND Vocabulary for Notes use wherever there is a or a in a table or weight pressure gradient clockwise of mercury to north stream ATMOSPHERIC PRESSURE AND WIND Summagy Chapter 5 looks at atmospheric pressure and wind and how they are related We will see how atmospheric pressure is measured Those home barometers that are given for gifts on Father s Day are part of the process of determining the weather Other topics include the in uence of pressure on wind ow and what we can high and low pressure areas Another part of the chapter looks at the circulation patterns of the world and the pressure patterns of the world A nal look at local winds such as sea breezes and seasonal changes in wind ow such as monsoon winds will give us useful information when we explore climate patterns Objectives To Successfully be Able to Explain 1 What initially sets air into motion 2 How the pressure gradient Coriolis force and friction affect air motion 3 The wind direction found for high and low pressure cells in the northern and southern hemisphere Misconceptions l A river and wind both owing north are moving in the same direction 2 Water always goes down the toilet bowl the same way in the Northern Hemisphere Did you Know 1 Windchill estimates are based on experiments done in the Antarctic to gauge the danger of frostbite Used to warn people of the risk of cold weather they can be misleading especially when the temperature is above freezing 2 It39s impossible for a hurricane to cross the equator because it would lose its rotational energy 3 The Coriolis effect pulls your car 1500 ft to the right for every 100 miles you travel Friction between tires and the road prevents this from happening The highest winds on earth typically occur in gusts like the 231 mile per hour wind recorded on Mount Washington This is the world record wind officially but radar found gusts in a 1991 Oklahoma tornado at 287 miles per hour 4 r n Tying it all together Last time we learned about the mechanisms that heat the earth s atmosphere chie y through the capture and reradiation of outgoing infrared radiation conduction convection and release of latent heat Today we learn that the uneven heating of the atmosphere creates conditions that create atmospheric pressure differences and in turn the wind Simply put differences in heating create differences in atmospheric pressure Differences in atmospheric pressure created a pressure gradient that produce wind OBJECTIVE 1 What initially sets air into motion Wind is simply the Wind direction the wind direction is the direction of which the wind is blowing A north wind blows from the north Wind direction is opposite of river direction The Mississippi T JPUHh Alnwsllhm River ows but a south wind travels 439 from Weight ofthaairinthecolumn applies prmsure to point 39X39 A In the space below draw an arrow kl representing a west wind and an T 39 arrow representing a west owing Sum river Assume the top of the page is north Unit Area k As pictured to the right atmospheric pressure is the exerted by the atmosphere ImageWW2010 2005 Sea mg image Pidwimey 2005 As pictured to the right 3ij an instrument that measures air pressure Wind velocity is measured by a device called an Almusnherk Freasure Pressure gradient force horizontal differences in pressure create wind This force causes the wind to blow The the pressure differences and the distance between the cities the strength of the wind unulner o Mercurv Temperature differences are responsible for initially creating a pressure gradient force Let s use a lit match to create a simple convective cell with a pressure gradient force Immediately above the match is a zone of low pressure as rising hot air creates a pocket oflow pressure Here the air is Units of Pressure less dense because air molecules have been heated Inch 5 of Mercury II quot Hg Atmuspheres arm Millibars p mb 3910quotl325 mb 2992 quotHg 10 atm andhave risen vacating the area The denser higher pressure air on either side ofthispocket of hot air moves in to replace the vacated air molecules The unit that atmosphericpressure is measuredis and Imagewwzolo 2005 Isobars on a weather map isobars are an isoline measuring an area of Isobars represen a weather map zones of 11000quot millibar intervals gradient Expect strong winds spacedisobars represent r L L L gentle 11L rm mm in Dakota Imageww201o 2005 So 39 39 39 pressure Horizontal differences in pressure create wind In other words air that is heated is mm 39 and oer e an 39 39 mi rising air E 39 L L L OBJECTIVE 2 39 quotMinquot 39M39l e 39 39 39 unidun Coriolis force 39 39 39 from its path In the Northern Hemisphere wind is de ected to the of its path 39 39 39 39 See an an mation ofthis phenomenon The Coriolis force only in uences the of the wind and not the ofthe wind wind speed Thi i another ie hnwn39 cells 39 39 L L J L the L cquot 39 exerted on the wind t u u 0 cc r r isobars at Imageww2010 2005 Winds behave di erently with altitude In the middle latitudes the winds on an upperlevel chart tend to blow 0 iso ars in amore or ess direction in both hemispheres See instructor animation The Eis ahigh 39 39 quot r Two39 39 39 neam 39 39 39 39 39 During the wintertime the po1ar jet dips south and marks the southern boundary of cold air In summer the po1ar jet retreats to Canada The subtropical jet moves north to rep1ace the po1ar jet producing mm temperatures OBJECTIVE 3 The wind direction found for high and low pressure cells in the northern and southern hemisphere air is found above a 1ow pressure ce11 A 1ow pressure ce11 or tat of1owest pressure A 1ow pressure ce11 then has air which converges andrises In the northern hemisphere a 1ow pressure ce11 rotates when viewed from above Look aElow pressure ce11 passes over Florida In the Southern Hemisphere surface winds b1ow clockwise Regardless of hemisphere a 1ow pressure wi11 alvmys be characterized by converging and f rising air air is found above ahigh center of low pressure pressure ce11 A high pressure ce11 Department a1 Atmospheric sciences or A runway itrimnunmmm high pressure cell is chmwedzed t1 by rotation which rom tt rrvthenyrmdh i an ct r diverges and descends In the northern hemisphere a high pressure cell circulates In the Southern Hemisphere surface winds circulate counterclockwise Regardless of hemisphere a high pressure cell will always be characterized by descending and diverging air In the space below draw how a high and low pressure cell would look in the plan 6 View as it would appear on a map and cross section if you were looking at it 1 39 from the side for both the northern and southern hemispheres KEY TERMS FOR GLACIERS AND GLACIAL LANDF ORMS Vocabulary for Notes use wherever there is a feet 8000 years ago sheets rebound lubrication iceburgs tilt valleys Plains alley glaciers tectonics Eruptlons or GLACIERS AND GLACIAL LANDFORMS Objectives To Successfully be Able to Explain 1 How glaciers form and move 2 The major classi cation scheme for glaciers 3 What causes glaciations 4 Characteristics of past and present glaciation 5 Erosion by glaciers particularly in relation to Michigan 6 Deposition by glaciers particularly in relation to Michigan 7 Glaciers produce changes in water bodies Misconceptions 1 Glaciers don t exist at the equator 2 Most of Alaska was glaciated during the last ice age 3 During glacier retreat glaciers stop turn around and move in an opposite direction 4 A glacier is formed when a body of liquid water freezes V 5 The39 Ice Age 6 Pure clean crystal clear glaciers 7 Glaciers are white 8 Nice to look at but in the big scheme of things glaciers aren39t all that important Did you Know 1 The longest glacier in the world the Lambert Glacier in the Antarctic is 64 Kilometres 40 miles wide and 515 kilometres 320 miles long 2 The fastest moving glacier the Quarayaq in Greenland moves about 82 to 1005 centimetres 27 to 33 feet per hour 3 Science discovered the movement of glaciers quite by accident In 1827 a Swiss scientist built a hut on a glacier When he came back three years later the hut had moved more than 91 metres 100 yardsdownhill 4 There are glaciers on the equator although only at very high altitudes where the temperature is sufficiently cold to ensure their survival 5 The body of a 5000yearold man frozen and perfectly preserved by a glacier was discovered in the spring of 1991 in the Austrian Alps E 39 Tying it all together Glaciers and glacial processes are firmly connected to the three earth spheres that we have studied previously Atmospheric 397 processes impact the growth movement and melting of glaciers The Lithosphere determines the effectiveness of glacier erosion and channels ice sheets into pre existing topographic features like mountain valleys or preglacial river channels The supply of water to the Hydrosphere is in part provided by glacier runoff The great rivers of Asia like the Ganges and Yangtze are fed by glacier runoff As the great ice sheets of Antarctica and Greenland melt sea level rise will threaten growing human settlement along coastlines Finally the Biosphere is impacted by glaciers As ice sheets melt less solar energy will be re ected into space creating a positive feedback loop in which surface albedo decreases warming the earth which melts more ice which further lowers albedo which further melts more ice Human and animal populations will need to adjust to shifting food supplies sea level rise earlier melting of the pack ice during the spring and later freezing of the pack ice during the fall Image httpimagesjupiterimagescomcommondetail07l92257l907jpg n bBJECTIVE 1 How glaciers form and move A Definition a large body of ice and snow lasting more than a year and capable of and internal deformation E B Formation Snow gt Fim gt Glacial Ice Click launch interactive Balance between accumulation addition of ice and of ice through melting and sublimation Ice moves away from the center of accumulation A good analogy for ice movement would be how thick pancake batter moves away from where it was initially poured Image httpwwwrainu1 39 39 formation gif 39 llllusua Eluvlul C Movement Once the ice becomes about 65 feet deep the sheer weight of its mass causes it to start moving under its own weight 1 since ice is less dense than water an increase in pressure lowers the melting point of ice thus with depth the pressure of overlying ice is sufficient to cause the glacial ice to form a thin lm of water allowing the glacier to and slide along its bed This action is similar to what happens when you go ice skating In between the blade on your ice skate and the ice there39s a thin sheet of water that s what allows you to glide along 2 When the weight of the ice presses down it causes the crystals of ice to form sliding layers the glacier then moves along by sliding on its layers An analogy would be glaciers slide by creep in a manner similar to the sliding of a deck of cards placed on a slope OBJECTIVE 2 The major classi cation scheme for glaciers l confined to mountainous regions valley glaciers move down from higher elevations along existing stream channels Several valley glaciers may join and form a larger valley glacier The is the elevation above which snow can persist throughout the year At the poles the snow line is at At the equator the snow line is over 20000 feet above sea level A typical valley glacier will add snow at its head and lose to melt at its terminus The snow line or is the line below which the annual snow cover is lost in E summer The region above the snowline is the zone of the region below where ice lost due to melting mass wasting and sublimation is the zone of If the glacier gains more snow ice and fim than it loses its terminus 5 will advance It loses more than it gains the glacier will retreat form where When a glacier encounters an increase in the slope of its bed E the surface is in tension ice moving apart Crevasses Click on Fig 129 Crevasses on a Glacier 1 137 OK close where compression occurs or ice caps are large accumulations of ice that ow laterally 2 under their own weight A continental ice sheet Click on Crosssection of an Ice Sheet 1 1920Kn forms at high latitudes when the winter accumulation of snow does not completely melt in the summertime More snow is added in subsequent years and the weight of snow pressing down on the layers underneath turns the older snow to glacial ice The weight of the snow and ice is also what causes the ice sheet to ow laterally Unconfined by topography these vast ice masses spread radially from highland centers of accumulation and cover lowlands to thousands of feet Where ice sheets border oceans or lakes the glacier will a i decreas1ng1ts mass Actually the classification scheme for glaciers is more complex than the simple one proposed here Access the glacier module 39 39 quot J39 39 39 J 39 Hst swf Click on the at httpwww llkv edu ASC Overview button at the top menu The first page of the module will be Types of Glaciers On the bottom left hand side of the page will be a Glacier Type pull down menu In the table below list all the different types of glaciers OBJECTIVE 3 What Causes Glaciation We39ve always had glaciation in fact 700 million years ago it is thought there were glaciers at E the equator Snowball Earth click on animation 231 The whole earth was thought to have been covered because of the growth of ice caps that produced a positive feedback loop More ice9 lower temperatures because of increased albedo9more growth of ice9 lower temperatures because of increased albedo 1 Movement of a continent over a polar region may induce glaciation Moving landmasses can also change ocean circulation patterns which could trigger an ice age For example if shifting landmasses caused warm Atlantic water to enter the Arctic Ocean it might not freeze over in winter and the resultant increase in moisture as snowfall might initiate a glacial advance The position of mountain ranges could be another trigger for glaciation by altering air circulation patterns 2 The Earth rotates on its aXis as it orbits the sun The angle of the aXis of rotation changes slowly when aXial tilt is greater than 23 12 degrees climatic extremes would increase perhaps triggering an ice age quotThe changes in the amount of solar energy reaching the Earth however are far too small to have any effect on the climate on their own Somehow they interact with the atmosphere and oceans becoming amplified into large differences in average temperature over the whole globequot Distance between the earth and sun plus variations in the wobble of the earth s aXis which determines the timing of the seasons also can also contribute to variations in solar insolation To access the animation access animation 222 Milankovitch Cycles 3 the increase in particulates from these two events could re ect enough solar energy to induce an ice age OBJECTIVE 4 Characteristics of past and present glaciation Glaciers Today about of the Earth39s water is contained in glaciers Of the nearly 15000000 square km of ice covered regions most ice is found in Antarctica and Greenland Currently almost of glacial ice is on Antarctica Glaciers can be found from Africa to Alaska If the all the world39s glaciers melted oceans would rise nearly Past Glaciers Pleistocene Epoch Glaciers Glaciations have occurred throughout earth history The most recent Ice Age was called the Ice Age which began about 15 million years ago Temperatures were about 14 degrees F lower Great continental ice sheets have covered much of the Northeastern US and most of Canada as well as northern Europe and Asia during the Pleistocene lhere were N rm prornlnent terrnlnal rnoralnes are found Nebraskan Kansan llllnolan wlseonslnan Eaeh of the years The wlseonslnan aolyanee reaeheollts peak only about and the last rernnants rnelteol away less than 7000 years ago age http www rnetateeh org mages ceiageglaclanonimap Jpg lee Sorne lee loadedterralns sank 1000 it Today lee only eovers about a ofthe earth39s surfaee t r t of 2 ernyr Hudson s Bay for example has rlsen 300 rn slnee the last glaelatlon The proeess by The two rnaln Plelstoeene lee masses were the lee sheet and Seandlnaman lee sheet OBJECTIVE 5 Ernsinn by glaciers particularly in relatlnn tn Michigan A Proeesses of Glaelal Eroslon A laelers plek up sedlrnents by breaklng offpleces ofrock a proeess ealleol or abradlng bedrock surfaces The scratches left behind by abrasion by rock fragments are called These striations align with the direction of ice movement is a second process of glacial erosion and occurs when large chunks of rock H are quarried by moving ice Why should you care about processes of glacial erosion if you are a Michigan resident 1 Many of the colorful ornamental rocks that decorate our yards driveways and parks originated from Canada These showy igneous and metamorphic rocks are often stripped with colorful patterns of sills and dikes and are quite different from the rather mundane grey and brown rocks sandstones shales and limestones native to the Lower Peninsula of Michigan Rocks transported by ice which are not native to the local type of bedrock are called 2 Most Michigan residents get their water from groundwater The sediment eroded by the glacier often reaches depths of hundreds of feet and serves as an or underground layer of porous sediment that yields water Most of us have swum in at least one of the Great Lakes The Great Lakes were created by glacial erosion Remember glaciers ain t In its journey southward from Hudson Bay if a glacier has a choice between climbing a hill or using a preeXisting river valley what do you think it is going to take Of course it s going to take the path of least resistence 7 the preglacial river valley The glacier widened deepened and straightened these preglacial river valleys creating depressions that B would eventually be filled by groundwater and ice meltwater creating the Great Lakes L V Here are some examples of erosional landforms which are primarily found in mountainous areas where alpine glaciers owed down mountain valleys under the in uence of gravity 1 The characteristic Vshaped stream valleys are enlarged by the action of glacial ice to a Ushaped profile a 2 Hanging Valleys tributary valleys that were not eroded as much as the main Ushaped valley When the ice retreats the main valley the tributary is at a higher elevation than the main valley Hanging valleys are often the site of waterfalls 3 A fiord is a deep rounded bottom steepsided cavity adjacent to the ocean These features were carved as the ice retreated from the valley Following the Ice Age these cavities were submerged when the sea level rose Fjords may reach depths as great as 3000 ft or more bowl like hollows where mountain glaciers originate Plucking occurs on the headwall abrasion on the oor The crevasse at the back of a cirque that separates the moving ice from the rock wall is called a bergschrund Tams ponds on the cirque oor 5 Aretesnarrow ridges between cirques as headwall cliffs behind two adjacent cirques erode back 5 Horns jagged rock spires occurring at the intersection of 3 or more cirques The Matterhorn in the Swiss Alps is probably the world s most famous horn OBJECTIVE 6 Deposition by glaciers particularly in relation to Michigan Glacial Deposits Glacial deposits include which forms from deposition directly from melting ice and which forms if sediments are transported and deposited by glacial meltwater streams Till is poorly sorted and generally unstratified due to deposition directly from melting ice Strati ed drift is better sorted and as the name implies stratified internally layered due to deposition in water Some landforms are made of till others are made of stratified drift deposits IV Glacial Deposits Glacial deposits include till which forms from deposition directly from melting ice and stratified drift which forms if sediments are transported and deposited by glacial meltwater streams Till is poorly sorted and generally unstratified due to deposition directly from melting ice Stratified drift is better sorted and as the name implies stratified internally due to deposition in water Some landforms are made of till others are made of stratified drift deposits A Deposited Sediment l Till is not layered unstratifred sediment transported directly by glacial ice It is very poorly sorted and can contain material from boulder to clay size sediment is layered stratified sediment sorted and deposited by uvioglacial meltwater Fluvioglacial material is usually composed of gravels and sands The term quotdriftquot is used if it is uncertain whether the sediment is deposited directly by the ice till or by meltwater uvioglacial sediment at httpwwwukveduASGeolo V howellgoodies lea 39 J 39 Hst swf Click on the Overview button at the top menu The sixth page of the module will be Glacial Sediemtn On the bottom left hand side ofthe page will be a Sediment Type pull down menu In the table below list all the different types of sediment quot Access the glacier module Which of the sediment types is wind deposited E B Depositional Landforms So why as a resident of Michigan should you care about material deposited by the ice Moraines serve as ski hills and provide a challenging par for golf courses The hundreds of feet of uvioglacial sediment deposited by the ice provides material for roadbeds and the manufacturing of glass The numerous kettle lakes throughout Michigan including portions of l Higgins and Houghton Lakes provide many recreational opportunities Differences in the types of sediment deposited by the ice also create belts of relatively rich soils and zones of relatively sterile soils Where the glacier deposited finer textured sediment such as clay and silts the soil tends to retain water and nutrients On the other hand where the glacier deposited gravels and silts soils tend to be droughty and infertile Image http gemini oscsmontanaeduNgeo1445hyperglacmeltwaterlkettlesjp g 1 material deposited from glacial bulldozing material deposited through mass wasting off the glacier or material deposited from meltwater streams These deposits mark the edge of a glacier forming ridges a terminal moraine marks the furthest advance of the ice into an area b lateral moraine unconsolidated material carried along the anks of a valley glacier Lateral moraines may form on top of existing alpine glaciers along the sides of the valley walls Freeze thaw weathering results in debris falling on top of the glacial ice forming a ridge As glaciers melt this material may be deposited on the landscape as a ridge c medial moraine formed on top of existing glaciers when two alpine glaciers ow together When these glaciers ow together their lateral moraines join forming a medial moraine a ridge in the middle of the glacier d recessional when glaciers begin to retreat there are often pulses of renewed activity which are marked by recessional moraines quotbehindquot the terminal moraine e ground as a glacier retreats or melts out in place sediment carried directly beneath the base of a glacier ice is left behind in place to drape bedrock 2 Eskersmeandering ridges of uvio glacial sediment deposited by streams owing through and at the bottom of a glacier 3 irregular rounded often cone shaped hills of stratified drift deposited by meltwater running off glacier sides into melt holes 4 f 39 39 39 39 deposits laid down in front of the retreating glacier The outwash plain may be dotted with kettles and laced with channels of former streams 5 A block of ice left in the outwash plain melts and leaves a hole which may fill with water 6 Drumlins streamlined oval shaped hills molded by the ice sheet into streamlined hills elongated in direction of ice movement The steeper side of the drumlin stoss side points upice OBJECTIVE 7 Glaciers produce changes in water bodies A Ocean Level Changes and Land Bridges During the Pleistocene much of the earth39s water was locked up in the form of ice consequently the Pleistocene sea level was lowered up to 300 feet Much of the continental shelves were exposed and some served as quotland bridgesquot Alaska to Siberia for example If all of the continental ice were to melt sea level would rise about 200 feet Many of the large metropolitan areas along the East and the Gulf Coasts would be underwater Access the Ifthe Ice Melts web page at httpwwwpbsorgwgbhnovavinsonicehtmlfea top and in the table 1 below list the East Coast cities that would be inundated if the East Antarctic ice sheet melted How much of Florida would be above water if the East Antarctic ice sheet melted B Proglacial Lakes water becomes dammed between the retreating ice mass and higher ground located away from the ice front Several proglacial lakes existed in Michigan Ever wonder why its so at between Mt Pleasant and Midland Or why it is so at around the Thumb of Michigan Both locations were sites of former proglacial lakes C Harbor Creation Rivers extended out onto the continental shelves and cut deeper channels in response the lowered base level When the ice melted and sea level rose many ofthese rivers became harbors especially along the east coast of North America KEY TERMS FOR SOILS Vocabulary for Notes use wherever there is a dioxide horizons SOILS Summa ESSENTIALLY ALL LIFE DEPENDS ON SOIL THERE CAN BE NO LIFE WITHOUT SOIL AND NO SOIL WITHOUT LIFE THEY HAVE EVOLVED TOGETHER iClark KellogiUSDA Image MOFGA 2007 httpWwwgarickbulkcomimagesproductsHandpottingisoiljpg July 19 2007 Objectives To Successfully be Able to Explain 1 What is soil 2 Select soil physical and chemical properties 3 Formation and characteristics of soil horizons 4 Role of earthworms Misconceptions l Weathering and erosion are synonymous 2 Soils are rocks 3 Most soils are classi ed texturally as sand silt or clay Did you Know 1 Michigan s state soil is the Kalkaska sand 2 Soils can be red orange brown red white and black in color L d Tying it all together Last session we learned the basics of climate the average weather over a period of 30 years is the weather Climate is the most important soil forming factor in uencing not only how quickly a soil will form but also its physical biological and chemical properties Thick well developed soil is often found where physical and especially chemical weathering helps create well de ned deep horizons On the other hand where little or no chemical weathering occurs as in desert or polar regions soil horizons are typically poorly developed and soils are thin L OBJECTIVE 1 What is soil Soil is composed of four r The fraction of soil is typically made up of tiny rock fragments that have been reduced in size by physical and chemical weathering another component of soils Sometimes water lls 5 Soil Components Ideal Soil Space portion Snlid portion 4 5 Inorganic Space VOIdS mmemls Also between individual soil particles 30 quot1ch Air is another component of soils The mgamsms soil they occur in atmosphere is richer in the space than the portion of soil above ground atmosphere because of 7 Orgalum plant respiration Finally usually makes up less than ve percent of soil volume yet organic matter in uences how easy it is to till the soil how well water and nutrients are retained and how well aerated the soil is for plant roots Image Purdue University 2007 httpwww hort mlrdne edn hn 39 thlsnrin S quot P r 39 439 im0005 incr accessed 9 July 2007 Thus soil is a surface layer composed of inorganic matter organic matter water and air and capable of supporting OBJECTIVE 2 Select soil physical and chemical properties pH is a soil chemical E property I is a measurement of soil acidity A pH of below 7 is considered a soil above 7 and a soil pH of7 is considered neutral a Most plants prefer a pH in the 65 to 75 range Acidic soils can be brought into the proper pH range by the addition of which is mainly calcium carbonate limestone Soil texture is the size of individual soil which are individual soil components If a soil is classified texturally as a soil individual soil separates are between 05 mm and 20 mm in diameter If a soil is classified texturally as a soil individual soil separates are between 05 mm and 0002 mm in diameter If a soil is classi ed texturally as a soil individual soil separates are less than 0002 mm in diameter Using the soil texture interactive list the soil texture classi cation for a soil that is 40 sand 40 silt and 20 clay Note enter these values in the upper right hand comer of the screen then click Submit 10 sand 45 silt and 45 clay 20 sand 50 clay 30 clay It is rare to nd a pure sandy silty or clayey soil Usually soils are mixtures of quot 39 several different size classes ranging from sandy size components to clay size 5 components Mixtures of sand silt and clay are termed soils Most soils are loamy soils with an additional textural descriptor added like sandy silty or clayey to describe the size fraction that predominates Example sandy loam sandy clay loam silty loam Given your knowledge the texture of sandy and clayey soils Fill in the table below using a rating of dif cult moderate and easy Soil Texture Ease of Tillage Abli y to retam Ability to retain water nutr1ents Sandy loam Clay loam Easy Silt loam Moderate View this interactive showing the relationship between surface area size and shape What would you conclude is the relationship between surface area and size What textural class has the greatest surface area OBJECTIVE 3 Formation and characteristics of soil horizons naturally occurring subsurface soil layers distinguished on the basis of physical color texture boundary chemical pH nutrient content calcium carbonate content and biological properties amount of organic matter presence of earthworms Soil horizons tell us a lot about the fertility of the soils In addition soil horizon properties help us distinguish one type of soil from another Soil horizons are formed by and chemical weathering Weathering is the breakdown of rock regolith and soil in place Physical weathering only involves a break down in Chemical weathering can involve either a breakdown in size or a chemical change transformation of bonds between elements or compounds or the substitution of new compounds or elements for existing compounds or elements involves the transport of weathered material Agents of erosion include glacial ice rivers wave action gravity movement mass wasting and wind a Horizon Designator There are four main horizons O A B and C horizons In the table below write the general characteristics of these horizons O OBJECTIVE 4 Role of earthworms The next time you are riding your bicycle on a rainy spring day steer clear of running over the lowly earthworm forced out of its burrow by ooding Earthworms perform a vital function in the soil by soil with its burrows soil with its waste products and organic matter throughout the soil On farms earthworms are sometimes poisoned by excessive fertilizer and pesticide use With earthworms absent extra fertilizers might need to be applied to soil Recently some concern has been expressed concerning the destructive roll that non native earthworms have in forests Apparently these earthworms devour the leaf litter that normally would accumulate on the forest oor removing a valuable source of nutrients for trees CLIMATE The maxL39s sy changes of olar radlahon g terrestrial I N202 radiation 2 Clouds c oem v w Za39ogols Atmosphereland Zv V upling Law This section focuses on global climates in uence of climate on the global distributional patterns of biomes and soils is then examined The biosphere is the least precise of the four principal components of the natural environment In many Ways it represents a response to the interactions of the atmosphere hydrosphere and lithosphere The climate the terrain and the Water features closely control the distribution ofnative plant and animal species over arth s surface The spatial distribution ofplant and animal life closely parallels the distributional patterns of the climates Soils are a product of the interaction between the lithosphere the atmosphere and the biosphere Maps portray the similarities in the global distribution of climate biomes and soils and their cause and effect relationships are readily apparent Image n CSIRO 200 httn39 www rmar r ir if accessed 19 June 2007 KEY TERMS FOR CHAPTER 8 CLIMATIC ZONES AND TYPES Vocabulary for Notes use wherever there is a or a in a table westerlies winds Stream emperamre CLIMATE Summary r 39 Initwe will quot quot classi cation system used in United describe by location characteristics and controls in the text an determining the climate classi cation image University ofCallfomla San Diego 2007 Objectives To Successfully be Able to Explain 1 Factors that in uence climate 2 The general characteristics ofA B C D and E climates Misconceptions 1 climate and weather and synonymous Did you Know 1 The sunniest city in the United States is Yuma Az which receives 90 ofpossible sunshine each year 2 Over the past 30 years more people have been killed by oods and ash oods than any other weatherrelated disaster 3 The record for the most snowfall from asmgle storm in the US belongs to Mt Shasta California where 189 inches fell from Feb 1319 1959 4 At 38 degrees below zero mercury in thermometers freezes so when it gets colder than this alcohol thermometers are used The Empire State Building in New York city is struck by lightning more than 20 times in an average year 6 Although Texas sees more tomadoes each year than any other state the state with the most tornadoes per 10000 square miles is Florida 7 On January 22 1943 the temperature at Spear sh SD went from 4 degrees Fahrenheit to 45 degrees Fahrenheit in just two minutes 8 The heaviest snowfalls usually occur when the air temperature is just below freezing but it is possible to see snow akes falling with temperatures in the upper 30s since it is much colder aloft where the snow akes form L a u Tying it all together In the last module we discussed factors that in uence the weather such as the unequal heating of the earth s surface Coriolis Force pressure differences precipitation humidity clouds wind fronts and storms When we talk about the weather we are talking about these phenomena either in real time or acting over a period of a few days for a certain location Weather can change from minute to minute or hour to hour The average weather over a period of 30 years is the weather Temperature and precipitation predictions for next summer for a certain location would be considered a prediction of climate The temperature and precipitation conditions happening right now or the day after tomorrow would be considered weather In this chapter we ll learn how latitude land vs water geographic position and altitude in uence climate h a u OBJECTIVE 1 Factors that in uence climate A Latitude Generally as latitude space below graph the relationship between latitude and temperature Which aXis X or y is the independent variable aXis Which of the two variables above is the independent variable Access the following web site on climate controls In the space below describe the how the temperature curves for the three cities below vary both in terms of their peakedness amplitude and actual temperature values What is responsible for the differences in amplitude Moosenae Atlanta Quito B Land vs Water pri r 1197 39se the 39 39 39 lot of t temperature ofa body ofwater Conversely however once water achieves a certain temperature it retains its heat energy much better than bodies ofland Lumiiuu um Locations near large bodies ofwater in the winter are Cities located near large bodies ofwater would have a climate experiencing moderate seasonal temperature differences Cities experiencing a Ievkiavik musk Q climate on the other hand are located well inland many miles away from a major body of water 39 continental extremes in temperature Source Carbone G 2005 Climate Controls L 39 D ec 2005 cited C Geographic Position Proximity to a large body of water isn39t the only thing to consider when evaluating maritime cimaes A 39 L quot quot Access the Geographic position web site Consider the climographs for San Francisco vs Norfolkwhat do you notice regarding temperature and precipitation patterns Temperature patterns Precipitation patterns Note that both cities are located on a large body of water both have a maritime climate when judged against St Louis Missouri Norfolk much less than San Francisco The the belt of wind that predominates between 30 and 60 degrees of latitude brings relatively warm winds to San Francisco These warm winds are chilled by the continental landmass during the winter warmed during the summer Consequently Norfolk s temperature patterns are much more extreme than San Francisco D Mountains In the space below graph the relationship between temperature and altitude Which axis x or y is the independent variable axis Which of the two variables above is the independent variable Given that temperatures decrease at around 35 F 1000 ft What is the temperature on top of Mt Washington 6200 ft given that temperature at its base 1000 ft is 75 F In Mt Pleasant 800ft temp 90 F altitude for a plane ying at 35000 ft In addition to the in uence of altitude mountain chains in uence precipitation patterns The i 39 39 for the observed increase in precipitation with altitude as air rises up a mountain slope click on launch interactive The side of large mountain chains have higher amounts of precipitation than the dry side of the mountain chain where E air descends warms and loses its capacity for precipitation Rain Shadows form where warm air descends on the lee side of mountains Examples of Rain Shadows would include the eastern portion of Washington State on the lee side of the Cascade Mountains and Nevada on the lee side of the Sierra Nevada Mountains E E Ocean Currents Seasurface temperature in uences local as the ocean exchanges heat with the overlying atmosphere It also in uences rates which are generally higher where seasurface temperature is higher One of the driest places on earth is the Atacama Desert located in Chili Despite its location along the coast the cold current offshore prevents the formation of unstable air that could give rise to showers In contrast the warm current increases the winter temperatures of Europe Water is never far from any location in Europe a continent of OBJECTIVE 2 The general characteristics of A B C D and E climates Using your textbook and the Koeppen interactive complete the table below Climate Climate Location Temperature Precipitation Comments Letter Name Summer I Winter Summer I Winter A B C KEY TERMS FOR HEATING THE ATMOSPHERE Vocabulary for Notes use wherever there is a or a in a table pm 5 1 arming avelength cooling HEATING THE ATMOSPHERE Summagy This begins your study of temperature a fundamental determinate of weather and climate The way the Earth is heated and cooled is discussed by demonstrating the effects and types of electromagnetic radiation that is emitted from the sun and from the Earth Also the processes of absorption radiation re ection scattering transmission conduction and convection are discussed as important in the ability of the Earth to be inhabited The factors that are important for the greenhouse effect and the part played by the oceans are s own Global temperature patterns and their relationship to the sun s movement are demonstrated as well as the changes in temperature resulting from elevation vertical temperature patterns and lapse rates Image Astronomycom 2007 httpWWWastronomycomasyobjectsimagessunifullidi5185011070971471997jpg cited 19 June 20067 Objectives To Successfully be Able to Explain 1 How radiation conduction convection and latent energy heat and cool the earth39s atmosphere 2 The variables involved in the earth39s radiation balance 3 The prominent controls of temperature Misconceptions 1 We can see most of the energy emitted from the sun 2 You never drank nor were heated by the former sweat of another person 3 The atmosphere is heated from above 4 Coldest temperatures usually occur in the middle of the night 5 Venice Italy with its palm trees and yearround gondolas is further south than Minneapolis Minnesota 6 Glaciers don t exist near the equator 7 Hawaii39s record high temperature is greater than Alaska s record high temperature 8 quot One only needs to worry about hypothermia when it is snowing and temperatures are in the thirties or belowquot quotDon t worry I ll like Phoenix summers it s a dry hea quot quotJack Daniels on a cold day is my warm friendiit feels sooo good going downquot t O O Did you Know 1 The hottest recorded temperature in the United States occurred on July 10 1913 in Death Valley CA It reached 134 Fahrenheit 56 degrees Celsius and that s in the shade 2 The highest temperature ever recorded in our northern most stateAlaska was 100 Fahrenheit The highest temperature ever recorded in our southern most state Hawaiiwas 100O Fahrenheit This is an example of the impact of continentality and the maritime in uence as a climatic control 3 The coldest recorded temperature was 1269 degrees Fahrenheit 883 degrees Celsius in Vostok Antarctica on August 24 1960 4 The hottest recorded temperature is 136 degrees Fahrenheit 58 degrees Celsius in El Azizia Libya on September 13 1922 Tying it all together We know that the sun39s energy is seasonally distributed by latitude This week we learn what happens to sun39s energy upon entering the atmosphere We will learn how conduction convection latent heat plus incoming and outgoing radiation heat are balanced so that temperatures within the troposphere are moderate Last week we learned of the importance of the atmosphere in terms of the greenhouse effect and stratospheric ozone Without the greenhouse effect we would be subjected to extreme temperatures Without stratospheric ozone we would be bathed in dangerous ultraviolet Iradiation OBJECTIVE 1 How radiation conduction convection and latent energy heat and cool the earth39s atmosphere 1 Radiation What is radiation Radiation is the transfer of without the involvement of a physical substance in the transmission Radiation can transmit heat through a vacuum Radiation sources vary as indicated by this animation Energy travels from the sun to the earth by means of electromagnetic waves The shorter the wavelength the higher the energy associated with it 1s A J in this animation With electromagnetic waves the shorter the wavelength the greater the amount of energy Most of the sun39s radiant energy is concentrated in the visible and nearvisible portions of the spectrum Shorterthanvisible wavelengths account for a small percentage of the total but are extremely important because they have much higher energy These are known as wavelengths Wave energy is emitted in three major classes of wavelenglhs ultraviolet visible and infrared After viewing this animation list at least three different types of infrared longwave energy two different kinds of ultraviolet shortwave energy and the correct color sequence of visible light from longer to shorter wavelength Wavelength is often measured in terms of A micron is 11000 of a mm 2 Conduction is the process by which heat energy is transmitted through with neighboring molecules Some solids such as metals are good conductors of heat while others such as wood are poor conductors Air is a relatively poor conductor Since air is a poor conductor most energy transfer by conduction occurs right at the earth39s surface At night the ground cools and the cold ground conducts heat away from the adjacent air During the day solar radiation heats the ground which heats the air next to it by conduction 3 Convection transmits heat by transporting groups of molecules from place to place within a substance Convection occurs in uids such as water and air which move freely In the atmosphere convection includes large and smallscale rising and sinking of air masses and smaller air parcels These vertical motions effectively distribute heat and moisture throughout the atmospheric column and contribute to cloud and storm development where rising motion occurs and dissipation where sinking motion occurs To understand the convection cells that distribute heat over the whole earth let s consider a simplified smooth earth with no landsea interactions and a slow rotation Under these conditions the equator is warmed by the sun more than the poles The warm light air at the equator rises and spreads northward and southward and the cool dense air at the poles sinks and spreads toward the equator As a result two convection cells are formed UCAR 2007 Introduction to the Atmosphere httpwwwucareduleaml l lhtm accessed 28 June 2007 ThennalS when differential heating occurs at the ground service a bubble or of warm air will rise from the surface Hang glider pilots and turkey vultures like to take advantage of thermals for a free lift 4 Latent Heat is heat that is taken up or released when water changes state from a solid to a liquid condensation from a liquid to a gas evaporation from a solid directly to a gas sublimation or from a gas to a solid deposition It cannot be measured by a thermometer Latent heat is also stored and released respectively for melting and freezing Evaporation is a process latent heat is stored within the water vapor molecule C J quot is a process latent heat is released into the local environment 9 EHOW cold can it get in Alaska The change is state observable in this video is a deposition b sublimation c condensation d evaporation e freezing f melting Phase change and temperature changes Describe the graph line when ice A melting and water is boiling Does the temperature change OBJECTIVE 2 The variables involved in the earth39s radiation balance 1 Losses in incoming energy Absorption is the retention of incoming solar energy by certain gases like ozone carbon dioxide methane CFC s water vapor and nitrous oxides In addition aerosols particulates like dust can absorb incoming energy Finally which make up clouds absorb incoming energy Scattering is the de ection of incoming solar energy into different directions Mie and Raleigh scattering are responsible for sky and cloud color Re ection a surface such as ice or water turns back radiation so that the radiation rebounds from the surface 2 Only of the sun39s energy reaches the earth39s surface In the Tropics the of energy reaching the surface is greater because the more direct angle of solar insolation reaching the surface In the midlatitudes and polar regions the concentration of energy reaching the surface is much more diffuse resulting in lower annual average temperatures 3 Losses and gains by outgoing energy What happens to the sun39s energy that reaches the earth Eventually energy absorbed by the earth becomes outgoing energy a Radiation outgoing energy leaving the earth is in the or longwave portion of the spectrum Some of this longwave energy will be absorbed by greenhouse gases and reradiated back to the earth s lower atmosphere warming the planet b Latent heat a process that will reduce temperatures in the lower atmosphere particularly near large water bodies c Convection density differences will carry parcels of warm air away from the surface thus cooling the lower atmosphere near the earth s surface What is the radiation balance Earth and its atmosphere some of the sun s energy resulting in the warming of the earth At the same time heat absorbed by the Earth and its atmosphere is radiated along with losses due to convection and latent heat back into space resulting in a cooling of the planet The between absorbed and radiated energy determines the average temperature Because the atmosphere is a better absorber of outgoing longwave energy rather than incoming energy from the sun the atmosphere is mainly heated from To test your A J39 of the earth s radiation balance a complete the following on line drag and drop exercise During the day the surface of the earth and the air above it will continue to warm as long as incoming energy mainly sunlight and reradiated atmospheric infrared energy exceeds outgoing infrared energy from the surface This typically occurs at Note that even though the sun s rays are most direct at solar noon the highest temperatures of the day typically lag by three to four hours Again this is due to the combined heating effect of incoming solar energy and reradiated atmospheric infrared energy At night the earth s surface cools by giving up more energy than it receivesa process called T r will continue to decline until about OBJECTIVE 3 The prominent controls of temperature Heat versus temperature often used interchangeably but there are important differences between these two terms Heat is the amount of energy transferred from one body to another because of temperature differences Temperature is the average rate of movement kinetic energy for the molecules of a substance A shot glass of Jack Daniels has a higher temperature than a bathtub of room temperature Jack The total amount of heat contained by the bathtub far exceeds however the amount of heat within the shot glass l Altitude in general the one goes into the atmosphere the the average temperature Normal lapse rate the rate at which temperature decreases with altitude The rate is usually around degrees F per thousand feet Use the normal lapse rate to calculate temperature at 18000 ft the height of several mountains along the equator in the Andes Mountains of South America if the temperature at sea level is 800 F Based on your calculation could glaciers exist at the equator Inversions ground cooling on a clear calm night will chill the atmosphere in contact with the ground Air several hundred feet above the ground will as a result be warmer than air in contact with the ground The result is that a layer of stable denser is trapped beneath a layer of warmer air Impact of inversions on pollution air pollution from industrial stacks and automobiles will be trapped within the layer of dense cool air 2 Latitude A Latitude temperature relationship With increasing latitude temperature generally Directness of sun39s rays the sun s rays are more direct within the Tropics Less direct in the mid and high latitudes Consequently temperatures are generally warmer within the Tropics B Daylength days will generally produce more ground heating If the Poles get near 24 hrs of daylight during their respective summers why aren t temperatures higher Consider the directness of the sun s rays While it is true that the high latitudes have long periods of daylight during the summer it is also true that the sun does not get very high above the horizon As a result the sun s rays have to travel through a thicker atmosphere reducing the effectiveness of solar heating 3 Land Water Contrasts large water bodies retain heat Such water bodies don t heat up rapidly in the or cool down rapidly in the Over a large land mass in winter temperature uctuations are greater with lower temperatures than locations adjacent to a large body of water Over a large land mass in summer temperature uctuations are greater with temperatures than locations adjacent to a large body of water Near a large water mass in winter temperature uctuations are more moderate with higher temperatures than locations found within the interior of a large landmass Near a large water body in summer temperature uctuations are more moderate with temperatures than locations found within the interior of a large landmass What explains for these observations There are at least four reasons 1 Speci c HeatWater s high speci c heat it doesn t heat up or cool down rapidly Note the constancy of ocean temperatures compared to the land surface in this animation 2 EvaporationEvaporational cooling which is particularly effective during the summer 3 Transparency and MixingEnergy from the sun has to transmit heat through an entire water column which takes a lot more time than a land surface which heats up rapidly Mixing of water further distributes energy heating the land during the winter and cooling it during the summer 4 Ocean CurrentsFinally warm ocean currents like the Gulf Stream keep Europe warmer than what it would normally be during the Northern Hemisphere winter Access the LandWater contrast interactive What is the high and low V temperatures for Reykjavik and Yakutsk Both cities have nearly the same latitude hence daylength is similar as is the directness of the sun s rays What explains for temperature differences 4 Cloud Cover generally speaking the the cloud cover the the temperature Thin high clouds tend to keep the earth warmer than if there is no cloud cover Low thick clouds by day tend to keep the earth cooler KEY TERMS FOR CHAPTER QINTRODUCTION TO LANDFORM STUDY Vocabulary for Notes use wherever there is a boundary tectonics of re divergent plate boundary convergence CHAPTER 13 INTRODUCTION TO LANDFORM STUDY n ou walk down the staeet ox path 0 ou category we usually xefex to as exoslon Soll ls made om lock that has weathered Into small particles The All around We can nd these evm m out backymds CHAPTER 14 THE LNTERNAL PROCESSES Sllmm m name Eanln r meet The matenal 39 empuons slneld Volcanoes composlte volcanoes law domes and clndex cones The sectaon on othex factors mete me sevenzl types offault you should be farmlnnwlth The IS also an Important sectaon on eanlnquakes and the measuremmt ofeanhquakes amaae July 2006 Tmmwe NA A ml 7mm Objectives To Successfully be Able 1 Explain 1 How the eanln IS smm ed ow the spxeadmg convexgent and taansfonn plate boundanes relate to the dlsmbuhon ofcontlnents mountams and eanlnquakes Misconceptions 959 509080 5 gt0 The location of earthquakes is random Continents don t move Earth is molten except for its crust Most of the world s most spectacular scenery was created by cataclysmic events An earthquake measuring 65 on Richter scale is 1 time more powerful than a 55 earthquake All rocks are heavy All rocks were never alive The location of volcanoes is random All volcanoes produce violent eruptions Did you Know 1 Some rocks can oat 2 Roughly 1000 tons of space dust enters the atmosphere every year and makes its way to Earths surface Los Angeles will be a suburb of the San Francisco in about 15 million years Olympus Mons on Mars is a volcano that rises 16 miles 26 kilometers Its base would almost cover the entire state of Arizona The world s deadliest recorded earthquake occurred in 1557 in central China It struck a region where most people lived in caves carved from soft rock The dwellings collapsed killing an estimated 830000 people A 1960 Chilean earthquake which occurred off the coast had a magnitude of 96 and broke a fault more than 1000 miles 1600 kilometers long Alaska is the most earthquake prone state eXperienceing a magnitude 7 earthquake almost every year and a magnitude 8 or greater earthquake on average every 14 years Florida and North Dakota get the fewest earthquakes in the states The Grand Canyon is billed as the world s largest canyon system Its main branch is 277 miles 446 kilometers long But let s compare Valles Marineris on Mars extends for about 3000 miles 4800 kilometers If added it to a US map it would stretch from New York City to Los Angeles In places this vast scar on the Martian surface is 5 miles 8 kilometers deep About 540 volcanoes on land have erupted in historic times No one knows how many undersea volcanoes have erupted through history The Anchorage earthquake had a magnitude of 92 whereas the San Francisco earthquake was a magnitude 78 This difference in magnitude equates to 125 times more energy being released in the 1964 quake and accounts for why the Anchorage earthquake was felt over an area of almost 500000 square miles Source httpwwwspacecomscienceastronomy10 liearthifacts70307225html a a Tying it all together This is a difficult chapter There are so many concepts to cover with material taken from earth s crust and rock cycle rocks plate tectonics earthquakes and volcanoes weathering and mass wasting Entire courses could be taught on any of these topics For a more detailed analysis of these topics please take a course in physical geology 39 Why does volcanism orogenies mountain building events 1 and earthquakes occur where they do Why are there fossils on the top of 20000 ftmountains Why does Antarctica have coal deposits Doesn t Africa and South America look like pieces in a puzzle We may even be able to answer why Los Angeles and San Francisco will one day be suburbs of one another How are canyons formed Why does my car rust and why are Michigan roads so bad during the winter These topics will be dealt with in a cursory manner only to give you a brief introduction how the plate tectonics and volcanism impact earth s surface and how weathering wear down the earth s surface while at the same time creating new features Later you ll also see how glacial and uvial processes wear down the earth s surface while at the same time creating new landforms L bBJECTIVE 1 How the earth is strati ed The Lithosphere39s Strati cation think of continental crust like oating icebergs in a sea mainly rocks This layer is up to 40 of oceanic crust km thick denser crust consisting mainly of These first two categories are broken into plates 8 km thick thhosphere Crust an unner mun Mantle Take an apple bite and 4 quot liken the thickness of b 3 the skin to the thickness of the earth s crust semi plastic layer about 80 to 300 km down Earth Structure Not to Scale upon which continental and oceanic crust move more rigid layer of ultramafic rock beneath the asthenosphere extending down to the outer and inner core of the earth Image httpwwwuwspedugeofacultyritterglossarylinlithospherehtml OBJECTIVE 2 How spreading convergent and transform plate boundaries relate to the distribution of continents mountains and earthquakes The earth39s crust is broken into eight major fragments or that wander the E planet at varying speeds 115 cmyr and J39 quot refer to creation movement and destruction of these plates Plate tectonics helps explain mountain building orogeny volcanism and earthquakes The decay of radioactive minerals which produces convection is the power source for plate tectonics Let s explore movement along three major classes of plate boundaries 1 A see Fig 322 occurs where two plates move away from one another like two conveyor belts moving in opposite directions From this spreading zone new crust is created along cracks called rift zones where magma wells up to the surface An oceanic example of a spreading boundary occurs along the Atlantic Ocean39s MidAtlantic Ridge where the North American and Eurasian Plates are created and moving away from each other Consequently the Atlantic Ocean is getting wider An example of continental breakup at the surface see Fig 1921 occurred when Saudi Arabia split away from the African Plate forming the Red Sea 2 A occurs where two plates collide There are three types of converging boundary A In Fig 1932 for 39 quot oceanic crust collides with less dense continental crust oceanic crust sinks and is consumed beneath the continental crust through a process known as subduction Subduction occurs where the Nazca Plate dives beneath the South American Plate Volcanism and mountain building orogenies result Offshore subduction often results in the formation of deep oceanic trenches 810 km deep Subduction also produces volcanism As oceanic crust sinks it is subjected to tremendous pressure Eventually portions of the plate melt to form magma Under pressure magma then finds its way through fissures in the earth39s crust to form volcanos and lava ows at the surface Converging boundaries ringing the Pacific Ocean are consuming its oceanic crust as a result the Pacific Ocean is getting smaller E B A second type of converging boundary is where two oceanic plates collide For 39 quot see Fig 1928 As in oceaniccontinental collisions one plate is subducted under the other creating a trench The Marianas Trench almost 11000 m is an example of this plate interaction Subduction also results in submarine volcanoes which rise above the surface to form to form island arcs the curved pattern of the islands mirroring the curved pattern of the offshore subduction zone E C A third type of converging boundav is called Fig 1933 for animation Here neither parcel of continental crust is subducted because continental rocks are relatively light and resist downward movement The Himalayan Mountains over 8000 m and Tibetan Plateau around 4600 m result where the Indian Australian Plate smashed into the Eurasian plate 50 million years ago The term given for continentcontinent collisions is suturing Suturing causes the crust to buckle forming folded mountain belts See additional class animation on the collision of India with Eurasia 3 Sometimes plates horizontally slide past one another with crust being neither created nor consumed see view 3 This type ofboundary is termed a Most occur on the ocean oor An example of a transform plate boundary is the San Andreas Fault in western California Land on the western side of the plate boundary which includes Los Angeles is located on the Paci c Plate and is moving northwest Located on the eastern side of the plate boundary is most of San Francisco on the North American Plate which is moving southeast Being on opposite sides of the plate boundary these cities are moving toward each other at a rate of 5 cmyr An eventual question to be resolved Is Los Angeles a suburb or Los Angeles or is Los Angeles a suburb of San Francisco Where movement along any of the plate boundary becomes locked stress builds and earthquakes can occur Ealthquakes occur as plates suddenly lurch past one another the seismic waves generated by the earthquakes can result in building collapse through violent ground shaking Volcanism is commonly associated with spreading and converging boundaries Major plate boundaries N01th American Plate North America western North Atlantic and Greenland South American Plate South America and western South Atlantic Antarctic Plate Antarctica and the quotSouthern Ocean Eurasian Plate eastern North Atlantic Europe and Asia except for India African Plate Africa eastern South Atlantic and western Indian Ocean Indian Australian Plate India Australia New Zealand and most of Indian Ocean Nazca Plate eastern Paci c Ocean adjacent to South America Paci c Plate most of the Paci c Ocean and the southern coast of California About two dozen minor plates also eXist Some of these more famous plates are the Arabian Caribbean Cocos Philippine and Juan de Fuca plates