geography exam prep Flashcards
what are the 3 types of weathering?
- mechanical
- chemical
- biological
describe mechanical weathering?
- freeze-thaw
describe chemical weathering?
- acid rain (mixed with pollution)
describe biological weathering?
- rocks that have been broken down by living organisms
what is a V-shaped valley?
- formed by erosion from a river or stream over time
what is erosion?
- the break down and transport of rocks (smooth and round)
what is a meander?
- as the river erodes to the right side then to the left side, it forms large bends
what is a waterfall?
- formed in the upper stages of a river where it follows over different bands of rock
what are the 3 stages of freeze-thaw weathering?
stage 1:
- water seeps into cracks and fractures in the rocks
stage 2:
- when water freezes, it expands about 9%. this wedges apart the rock
stage 3:
- with repeated freeze-thaw cycles, the rock breaks off
what is deposition?
- when the river loses energy
describe hydraulic action in erosion?
- the sheer power of the water as it smashes against the river banks
what are the 3 factors leading to deposition?
- shallow water
- slower velocity at the end of the rivers journey
- when the volume of water decreases
describe solution in erosion?
- a chemical reaction that dissolved rocks
describe abrasion in erosion?
- when pebbles grind along the river bank and bed in a sandpapering effect
describe solution in transportation?
- minerals dissolve in water and are carried along
describe traction in transportation?
- large, heavy pebbles are rolled along the river bed
describe saltation in transportation?
- pebbles that bounce along the sea/river bed
what is transportation?
- natural process which is eroded
what are the 4 types of erosion?
- hydraulic action
- abrasion
- attrition
- solution
what are the 4 types of transportation?
- traction
- saltation
- suspension
- solution
describe attrition in erosion?
- rocks that bash together to become smooth/smaller
