OPTION C: EXTREME ENVIRONMENTS

terminology from my teacher/class

abrasion

a type of erosion that occurs when a transported material wears away at a surface over time

attrition

a type of erosion of rocks and pebbles knocking into each other and wearing down into sediment

buttes

isolated hill with steep, vertical sides and a small flat top

chemical weathering

process of chemicals in rainwater changing the minerals in a rock

corrasion

type of erosion of the earth’s surface caused by the transportation of materials (in rivers, glaciers, wind, gravitational movement)

creep

slow downward movement of particles/soil on a slope

deposition

the transportation of sediment (carried by wind, water, ice).

differential erosion

irregular erosion, or occuring at varying rates. caused by different hardnesses and resistance in materials.

dunes

a mound of sand formed by wind

erosion

earth materials being worn away (and transported by natural processes)

hydration

a type of chemical weathering where the chemical bonds of a mineral are changed as it interacts with water

insolation weathering

a type of physical weathering where a rock is repeatedly heated and cooled over daily cycles, breaking apart the grains.

mesas

a flat topped mountain or hill

oxidation

the breakdown of rock by oxygen and water

physical weathering

processes that break apart rocks without changing their chemical composition

rock pedestals

a rock which resembles a mushroom, formed by erosion and abrasion.

salt weathering

a type of physical weathering where salt crystals grow and expand in the cracks of rocks.

saltation

the bouncing of sand and pebbles at the bottom of river beds which are picked up and dropped by moving water.

solution

a type of chemical weathering where water dissolves certain types of rocks.

suspension

a method od transporting very fine sediment in a river.

wadi

a low, dry valley/ravine that only carries water during rainy seasons.

weathering

a process of wearing/breaking down rocks while they are in place.

wetting and drying

rocks containing clay materials expand when wet and contract when dry, this causes breaking and cracking.

plucking

as ice and glaciers move, they scrape the surrounding rock and pull away pieces.

freeze-thaw weathering

a process of erosion where water fills a crack, freezes and expands, making the crack larger.

periglacial

a zone peripheral to glaciers

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a zone/area which undergoes seasonal freeze-thaw weathering

arid

a region which receives less than 250 mm of rain each year

semi arid

a region which receives between 250 and 500 mm of rain each year

ice sheet

a mass of glacial ice larger than 50,000 square kilometers

glacier

massive bodies of slowly moving ice

permafrost

any ground that remains frozen for more than 2 years continuously

tundra

a biome with little to no treegrowth due to cold and windy temperatures. three types: alpine tundra, arctic tundra, and antarctic tundra.

arete

a thin sharp crest which used to separate 2 glaciers

u-shaped valley

the result of glaciers moving in and scraping the sides of the land/rock

hanging valley

a side valley which enters a main valley at high elevation

cirque

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corrie

bowl-shaped depressions that glaciers carve into mountains and valley sides at high elevations.

erratics

large rocks/boulders which are picked up by glaciers and dropped in foreign environments.

terminal moraine

material deposited at the end of a glacier

lateral moraine

material deposited on the sides of a glacier

medial moraine

material deposited between 2 glaciers (moving together)

glacial trough

a u-shaped valley forming from glacial erosion.

glacial lake

a lake which originated from a glacier/glacial activity.

pyramidal peak/horn

a mountain feature formed from several cirques on all sides.

thermokarst

the uneven settling of the melted permafrost beneath the top layer of ice/snow, creating sinkholes and quarries.

pingos

a dome-shaped hill formed from a permafrost area when the pressure of freezing groundwater pushes up a layer of frozen ground.

patterned ground

when the soil freezes and stones rise to the surface, the finer sediment creates patterns/shapes.