Origin of LakesOrigin of Lakes

Party FactsParty Facts

Lakes cover 2% of the earth's surface (2.5 Lakes cover 2% of the earth's surface (2.5 x 106 kmx 106 km22))Largest purely freshwater lake is Lake Largest purely freshwater lake is Lake Superior (83,300 kmSuperior (83,300 km22))LaurentianLaurentian Great Lakes Great Lakes

A A -- 245,420 km245,420 km22

V V -- 24,620 km24,620 km33

Lake Baikal Lake Baikal

20% of the world's fresh water20% of the world's fresh waterWorld's deepest lakeWorld's deepest lakeMaximum depth (Maximum depth (zzmm) ) –– 1620 m1620 mMean depth (z) Mean depth (z) –– 740 m740 mV V -- 23,000 km323,000 km3Of 1200 species of animals and 600 Of 1200 species of animals and 600 species of plants found in Lake species of plants found in Lake Baikal,overBaikal,over80% of the 80% of the taxataxa found in open water are found in open water are endemicendemic

Tectonic basinsTectonic basinsLakes formed by volcanic activityLakes formed by volcanic activityLakes formed by landslidesLakes formed by landslidesLakes formed by glacial activityLakes formed by glacial activitySolution lakesSolution lakesLakes formed by fluvial actionLakes formed by fluvial actionLakes formed by windLakes formed by windLakes associated with shorelinesLakes associated with shorelinesLakes formed by organic accumulationLakes formed by organic accumulationLakes formed by behavior of higher Lakes formed by behavior of higher organismsorganismsLakes formed by meteorite impactLakes formed by meteorite impact

Tectonic BasinsTectonic Basins

Depressions formed by movement of Depressions formed by movement of the earth's crust (e.g. warping, the earth's crust (e.g. warping, fracturing, faulting, thrusting). fracturing, faulting, thrusting).

Does not include volcanic activity.Does not include volcanic activity.

Fort RockFort Rock

Single fault displacement Single fault displacement ((orogenesisorogenesis))

Broken fault blocks which may become Broken fault blocks which may become slightly and irregularly tiltedslightly and irregularly tiltedExamplesExamples–– AbertAbert Lake, ORLake, OR–– Walker lake, NVWalker lake, NV–– Lake Winnemucca, NVLake Winnemucca, NV

Walker LakeWalker Lake

DownfaultedDownfaulted troughs or troughs or grabensgrabens((orogenesisorogenesis))

Elongated area is depressed and lake Elongated area is depressed and lake lies in bottom depressionlies in bottom depressionOften difficult to distinguish between Often difficult to distinguish between single fault single fault deplacementdeplacement and and grabensgrabens–– TuleTule Lake and Lower Klamath Lake are Lake and Lower Klamath Lake are

single fault displacement basins but are single fault displacement basins but are surrounded by lake sediments deposited in surrounded by lake sediments deposited in Pleistocene Pleistocene grabengraben lakeslakes

TuleTule LakeLake

DownfaultedDownfaulted troughs or troughs or grabensgrabens

ExamplesExamples–– Lake Tahoe, CA Lake Tahoe, CA

ZZmm -- 501 m501 m–– Lake Lake LahontonLahontonComplex of fault troughsComplex of fault troughs–– Lake BaikalLake Baikal–– Lake TanganyikaLake Tanganyika

Lake TanganyikaLake Tanganyika

Uplifted basins (epeirogenesis)Uplifted basins (epeirogenesis)

Marine depressions upliftedMarine depressions upliftedExamples Examples –– Lake Okeechobee, FLLake Okeechobee, FL

Lake OkeechobeeLake Okeechobee

Uplifted basins (epeirogenesis)Uplifted basins (epeirogenesis)

Uplifted plainsUplifted plainsExamplesExamples–– Great Salt LakeGreat Salt Lake–– Lake VictoriaLake Victoria–– Lake TiticacaLake Titicaca

AltiplanoAltiplano was raised 4000 m during the formation was raised 4000 m during the formation of the Andes during the Tertiaryof the Andes during the Tertiary

Lake TiticacaLake Titicaca

Lake TiticacaLake Titicaca

Great Salt LakeGreat Salt Lake

Uplifted basins (epeirogenesis)Uplifted basins (epeirogenesis)

Subsidence basinsSubsidence basins–– Often formed by earthquakesOften formed by earthquakes–– Often porous, therefore dryOften porous, therefore dryExamplesExamples–– ReelfootReelfoot Lake, TNLake, TN

ReelfootReelfoot LakeLake

ReelfootReelfoot LakeLake

Lakes formed by Glacial ActivityLakes formed by Glacial Activity

Pleistocene Pleistocene glaciationglaciation produced more current produced more current lakes than any other process of lake formationlakes than any other process of lake formationFour major episodes in Northern HemisphereFour major episodes in Northern Hemisphere–– Wisconsin glacier began to retreat 17,000 years ago Wisconsin glacier began to retreat 17,000 years ago

and stopped 10,500 years agoand stopped 10,500 years ago

Glaciers begin in mountain ranges and extend in Glaciers begin in mountain ranges and extend in ice sheets across flatter topography (piedmont ice sheets across flatter topography (piedmont glaciers)glaciers)

Glacial LakesGlacial Lakes

GlaciersGlaciers

Pleistocene GlaciersPleistocene Glaciers

MorainalMorainal DepositsDeposits

Lakes associated with active glaciersLakes associated with active glaciers

Lakes form on, within, beneath, and below Lakes form on, within, beneath, and below thawing glaciersthawing glaciersExamplesExamples–– LaurentianLaurentian Great LakesGreat Lakes

Lakes on GlaciersLakes on Glaciers

Ice scour lakesIce scour lakes

Ice moving over fractures removes rubble Ice moving over fractures removes rubble along fracture along fracture ExamplesExamples–– Diamond Lake, ORDiamond Lake, OR–– Crescent Lake, ORCrescent Lake, OR–– Waldo Lake, ORWaldo Lake, OR–– Odell Lake, OROdell Lake, OR

Waldo LakeWaldo Lake

Odell LakeOdell Lake

Cirque lakes (or tarns)Cirque lakes (or tarns)

Formed in upper portions of glaciated valleys Formed in upper portions of glaciated valleys of mountainous areas by repeated freezing of mountainous areas by repeated freezing and thawing actionand thawing actionAmphitheatreAmphitheatre--shapedshapedWater held behind rock or Water held behind rock or morainalmorainal sillsillGenerally small and relatively shallow (<50m)Generally small and relatively shallow (<50m)Often one above another Often one above another -- "hanging" lakes"hanging" lakesExamplesExamples–– GrinnelGrinnel Lake in Glacier National ParkLake in Glacier National Park–– Bull Run Lake, ORBull Run Lake, OR–– Aneroid Lake, ORAneroid Lake, OR

Cirque LakesCirque Lakes

Cirque LakesCirque Lakes

Upper Bull Run LakeUpper Bull Run Lake

Lakes below snow lineLakes below snow line

Paternoster lakesPaternoster lakes–– Corrosive action of ice forms chains of rock Corrosive action of ice forms chains of rock

basins within glacial valleybasins within glacial valleyExamplesExamples–– Glacier National ParkGlacier National Park–– Yosemite National ParkYosemite National Park–– Bighorn Mountains, WYBighorn Mountains, WY

Glacial TroughGlacial Trough

Paternoster LakesPaternoster Lakes

Lakes below snow lineLakes below snow line

Fjord lakes Fjord lakes –– Low elevationsLow elevations–– Long, narrow lakes in deep, steepLong, narrow lakes in deep, steep--sided sided

valleysvalleysExamplesExamples–– KootenayKootenay Lake, B.C.Lake, B.C.–– Lake Lake OkanaganOkanagan, B.C., B.C.–– English Lake DistrictEnglish Lake District

Fjord LakesFjord Lakes

Fjord LakeFjord Lake

Loch NessLoch Ness

Loch NessLoch Ness

Lakes below snow lineLakes below snow line

Piedmont lakesPiedmont lakes–– Low elevationLow elevation–– Glacial scouring in weak areas of parent Glacial scouring in weak areas of parent

geologic materialgeologic materialExamplesExamples–– Great Slave LakeGreat Slave Lake–– Great Bear LakeGreat Bear Lake–– Great Lakes of St. Lawrence drainageGreat Lakes of St. Lawrence drainage

Lakes formed by Lakes formed by morainalmorainal depositsdeposits

Lateral Lateral morainalmorainal damsdams–– Moraine deposited across the mouth of tributariesMoraine deposited across the mouth of tributaries–– More VMore V--shapedshaped–– ExamplesExamples

Finger Lakes of New YorkFinger Lakes of New York

Finger LakesFinger Lakes

Finger LakesFinger Lakes

Finger LakeFinger Lake

Lakes formed by Lakes formed by morainalmorainal depositsdeposits

Terminal Terminal morainalmorainal depositsdeposits–– Moraine left behind retreating glacier with Moraine left behind retreating glacier with

corrosioncorrosion–– More UMore U--shapedshaped–– ExamplesExamples

Wallowa Lake, OR (also associated with lateral Wallowa Lake, OR (also associated with lateral moraines)moraines)Flathead Lake, MTFlathead Lake, MT

Wallowa LakeWallowa Lake

Wallowa LakeWallowa Lake

Lakes formed in ground moraineLakes formed in ground moraine

Deposition of Deposition of meltwatermeltwater outwashoutwashDrift left behind with blocks of ice mixed inDrift left behind with blocks of ice mixed inKettle lakes form where ice blocks meltedKettle lakes form where ice blocks melted–– Very irregular in shape, slope, and Very irregular in shape, slope, and

topographytopography–– Generally shallow (<50 m)Generally shallow (<50 m)–– ExamplesExamples

Walden PondWalden PondTrout LakeTrout Lake

Walden Pond Walden Pond -- Kettle LakeKettle Lake

MorainalMorainal Deposits and Kettle LakesDeposits and Kettle Lakes

Kettle Lake FormingKettle Lake Forming

Lakes formed from effects of permafrostLakes formed from effects of permafrost

Cryogenic lakes Cryogenic lakes -- formed by effect of formed by effect of frozen groundfrozen ground coalesce and forms larger coalesce and forms larger lakes lakes -- thermokarstthermokarst lakeslakes

Volcanic ActivityVolcanic Activity

GraniticGranitic or basaltic nature of parent or basaltic nature of parent material causes low concentrations of material causes low concentrations of nutrients and, therefore, low productivitynutrients and, therefore, low productivity

Crater LakesCrater Lakes

Cinder conesCinder cones–– Small, conical lakesSmall, conical lakesExamplesExamples–– Crater Butte Lake in Mount Lassen National Crater Butte Lake in Mount Lassen National

Park, CAPark, CA

MaarsMaars

Created by explosive eruption of lava Created by explosive eruption of lava coming in contact with groundwater or coming in contact with groundwater or degassing of magmadegassing of magma–– Circular and very deepCircular and very deep–– Small Small -- b< 2kmb< 2kmExamplesExamples–– Lakes in Lakes in EifelEifel district of Germanydistrict of Germany–– Big Soda Lake, NVBig Soda Lake, NV

CalderasCalderas

Created by subsidence of the roof of a Created by subsidence of the roof of a partially emptied magma chamberpartially emptied magma chamberUsually larger than Usually larger than maarsmaarsExamplesExamples–– Crater Lake, ORCrater Lake, OR

Second deepest lake in North AmericaSecond deepest lake in North AmericaSeventh deepest lake in the worldSeventh deepest lake in the worldCollapse of peak of Mount Collapse of peak of Mount MazamaMazama in 4500 B.C.in 4500 B.C.A A -- 64 km64 km22

ZZmm -- 608.4 m608.4 m

Crater LakeCrater Lake

Crater LakeCrater Lake

Lava Flow LakesLava Flow Lakes

Coulee Lakes Coulee Lakes -- Depression formed by collapse Depression formed by collapse when overlying layers of a lava flow hardens and when overlying layers of a lava flow hardens and underlying layers continue to flow and leave underlying layers continue to flow and leave voidsvoidsIrregular lava flowsIrregular lava flows–– Examples Examples

Yellowstone LakeYellowstone Lake

Damming by lava flowsDamming by lava flows–– ExamplesExamples

Clear Lake, ORClear Lake, OR

Yellowstone LakeYellowstone Lake

Yellowstone LakeYellowstone Lake

So What?So What?Does this stuff make any Does this stuff make any

difference?difference?