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
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
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.