Exam 4

-material ejected with high force

-rocks= "bombs"

-devestating for human health

-move fast so you can't escape

-mt.st. helens

-composite

-snow and ice accumulation

-debris cloud moved long distances

-conifer forest destroyed

-lot of debris flow clogging rivers

-25 yrs later: mudflow is still visible on rivers

-short distance transport of material under gravity

-classified based on speed and amount of water

-mudflow=wetest and fastest

-creep=slowest and dryest

-rockfall=dry but fast

-cover everything in path; DESTRUCTIVE

-triggered by rainfall or volcanoes or deforestation or fire

-wet=travel longer distances

-fast

small or large

-not as devestating=drier

-fast

-rainfalls or earthquakes

-regolith (rock column) can fall too

-collapse of slope (Devestating)

-not a fluid flow, just rock and soil

-landslide scars=inverted v's

-fast

-move slow=not damaging

-form lobes and terraces

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-slowest and driest

-tilted pole or out of aliegned fences

-ripples

-cucles of wet-dry or freeze-thaw

-from burrowin ganimals and grazers

-curved tree trunks

-soil flowage

-common in tundra=too cold fro trees=scrubs/grassland=no tree stabalization of slope

-solifluction lobes

-higher altitude freeze-thaw and higher latitudes

-soil development is slow and not thick

-huge bolders

-breakdown of rocks into smaller and smaller rocks

-agents=H20, CO2, O2, organic acids, pollutants (sulfuric acid), temperature

small and numerous

-between grains and crystals

-ubiquitous

-occur everywhere; common

-joint systems

-larger scale

-individual, not sets

-desplacement of material

-igneous rocks that form when they cool

-pockets of air

-sedimentary/limestone/dolomite

-can form caves

-physical

-splitting of rock at high altitudes

-freeze-thaw cycles

-water goes in cracks and freeze at the top, expands into the interior of the rock=deeper and bigger cracks

-physical

-arid climates: wet-dry cycles

-water evaporates=salts=expands=big/deep cracks

-high latitude and altitude

-no soli/vegetation to protect rock

-expands with heat and contracts with cooling\

-ie fire

-physical

- removal of stress on rocks.

-peeling off of layers=exfoliation domes

-chemical: change in composition of rock

-electrons transfered from one region to another. O2.

-rusting of iron=different color (oxisols)

-eventually form soil

-chemical

-H20 and minerals ie silicate

-mineral expands=weakening along zones of contact

-chemical

-H20 and CO2 (carbonic acid)

-sedimentary rocks

lichens: form acids=disintegration of rock. expand and contract=flaking off of rocks

plant roots: on basalt lava flows seeds burrow into rocks and roots break through joints

-increases surface area

-increase T and precip=more weathering

-formation of caves: dissolution and precip

-increased precip, sedimentary rocks

-cave of the mounds

-joints allow air to  move in the rock

-dissolution-disolved

-precip=stalactites (ceiling) and stalagmites (ground)

-hilltops--haystack hills. residuals that havent weathered away

-weathering under the surface; caves under ground that collapse=sink hole

-s. part of WI

-water moving on landscape. unchannelized; interfluve

-through channels. valleys

-karst topography. caves

-water goes here.

-small or large

-valleys=stream flow and interfluve areas are flat

-physical impact of water drops

-no vegetation protection.

-overland flow

-water can no longer be absorbed by soil

-sheets of water movin gon surface

-overland flow

-finds a depression and forms channels

-channelized flow=stream

-over many storms (1000s yrs) rills deepen and form gullys

-large volume and speed of water

-smallest material

-salts/particles that dissolve in water

-can travel long distances

-in solution but not dissolved

-clay, silt

-most of the material that's transported

-straight=maximum velocity and erosion in middle

-most erosion are on edges of curve though

-outer curve=erosion; inner curve=deposition of material

-irregularities in stream bed. zones of intense weathering on rocks

-water digs down into the stream bed and eats away at weaker strata. stream bed can lower

-upstream migration of knickpoints overtime.

-valley deepens upstream

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resistant  /

weak      / 

resistant/____________

-deposition on inside curve, erosion on outside curve

-floodplain=fertile and lots of water...people like

-at headwaters and at mouth

-headwater erosion: eating away at interfluve area so valley lengthens

-mouth of river: deposition of material creates new landscapes=delta formation

*mississippi drainage basin covers 1/3 of usa

water flowing back and forth.

common

erodes outside curve deposits on inside

-low volume of water but lots of material

-stream is divided into interwoven streams

-short

-water flow is constrained by geography or modified by humans

-as time increases so does peak strea flow in urban areas (cement)

-in rural areas increase in time=decrease in peak stream flow (changing agricultural practices)

-little vegetation cover and little precip

-evapotranspiration>precip

-but moving water is still impt in shaping the landscape

-differential erosion: different material that weather and erode at different rates

-ranges of mountains with flat basins inbetween

-diversity of rocks (sed, meta, igenous)

-basins used to be lakes=accumulation of salt

-ie death valley

-alluvial fans---deposition of material |

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-flat tables and the mountain

-less erosion on mor resistant material=large cliffs/scarps (similar to knickpoints)

-weathering along joints=badlands

-physical weathering is more impt; not a lot of biological activity=salt wedging

-peaks of very resistant rocks=diofferential erosion

-walls of resistnat rocks

-material underneath has been washed away

atmospheric circulation=cool dry air from hadley cell

-rainshadows

-desert pavement(regs): not all deserts have sand. little soil development. creates more erosion

-wind transports material but doesn't shape topography as much as fluvial:dust storms

-suspended load and bedload (Creep)

-travel long distances---across oceans

-accumulation of fine silt material

-wind deposits it

-located in different places than todays deserts (where deserts were in the past)

-2 m yrs-last 10 t yers

-last glacial maximum= 20 t yr ago

-1/3 of the earth was covered in ice

-now we're in low ice=holocene

-edges of ice sheets are constantly moving; dynamic

-continental ice sheets: large, moving along landscape

-mountain glacier: high altitude in mountains, smaller

-physical: scraping/abrasion

-striations and grooves

-carving of vallies (mnt glaciers)--wider and U shaped

-roche moutonnee=smoothing of surfaces

-transports more material than streams

-all different sizes and types of material

-terminal moraine=furtherst glacier got where lots of till was deposited

-recession moraine=whatevers left on glacier is deposited

-till deposits-slanted

-cone shape mound of deposited material

-depressions left behind by glacier and get filled with water

-picking up rocks and carrying them long distances

-erratic boulders that don't look like anything nearby

-glaciers also cause irregular steam patterns