#14 Mass Movements
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Transcript of #14 Mass Movements
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MassMovement
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First,letsfinishaboutfriction Friction Theresistancethatonesurfaceorobjectencounterswhenmovingoveranother
F(downslope force)Ffric (upslopeforce)
Gravityisconstantbuttheslope()changes As increases,sodoesF
WhenF>Ffric ..
GSC350NaturalDisasters
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First,letsfinishaboutfriction Friction Theresistancethatonesurfaceorobjectencounterswhenmovingoveranother
F(downslope force)Ffric (upslopeforce)
Gravityisconstantbuttheslope()changes As increases,sodoesF
WhenF>Ffric ..
GSC350NaturalDisasters
M
N
F
Ffric
Gm
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Sinholes occurwhenoverlyingmaterialcollapsesintoanunderlyingvoid
Limestone(acommonsedimentaryrock)issolubleinacidscarriedbyH20(acidrain)
Undergroundcavernsform (avoid)
Overburdenmaterialwillcollapseintoit
GSC350NaturalDisasters
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NotcommonhereontheWestcoast,butbackeast,largeareasoflimestoneexistandcanbeveryporousduetodissolutionofbedrockwithinthewatertable(Karst landscape)
GSC350NaturalDisasters
Easilydamagestructuresbycompletelywipingoutthefoundation
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Alargefeaturethatisgenerallynotnoticeableonthehumanscale
Naturalprocessisgroundsettlingduetochangesunderground Occurduetovariousprocesses,butmostwidespreadtodayismaninduced
Groundfluidextraction(Oil,Gas,andH20)
Thawingpermafrost (maninduced?)
GSC350NaturalDisasters
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Fluidextractionfromthegroundleavesavoid
Duetolowerpressureinopenpores,overbearingrockcompressesdownwardtofilltheminExtractionofgroundwater
GSC350NaturalDisasters
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GSC350NaturalDisasters
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Permafrost isgroundthatcontainsfrozenwater(frozenground)
Severalfactorsleadtothethawingofthismaterialwhichmeltstheentrappedice Occursseasonally(wintertosummer) Occurslongterm
Humanconstruction(roads,pipelines) Longtermeffects(globalwarming)
Terraincanbecomepronetolandslidesandsubsideinanunevenmanner
GSC350NaturalDisasters
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GSC350NaturalDisasters
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GSC350NaturalDisasters
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GSC350NaturalDisasters
Hurricanes
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