Weathering/mass wasting Flashcards
What is weathering?
the breaking down and changing of rocks as a result
of exposure to the environment
What is Erosion?
the transportation of sediments that have been broken
down by weathering processes
methods of physical weathering:
Frost Action:
* Any water trapped in the crack, freezes and forces the crack to expand
Root Wedging:
* When plant roots grow within the cracks of the rock and eventually
break apart the rock as the root gets larger
Exfoliation:
* Dramatic temperature differences between night and day, eventually causes the rock to crack
and start to peel away
Abrasion:
* Most common method of physical weathering
What is chemical weathering?
The altering of rocks as a
result of exposure to
different substances
What is differential weathering and why does it happen?
weathering that happens at different times.
Soils differ based on slopes why?
Soils are generally thin or nonexistent on steep slopes for 2 reasons:
1. The water required for chemical weathering runs off of the steep slopes
2. Any soil that does accumulate would wash away downhill
Soils are thickest in lowland valleys
What is Liquefaction? How does it happen?
shaking from an earthquake causes sediment to lose grain-to-
grain contact and strength so what used to act like a solid (soil)
will now behave like a liquid
What is mass wasting? What are some factors that affect/contribute to mass wasting?
Mass Wasting is:
◼ Downslope motion of rock, soil, sediment, snow, and ice
◼ Driven by gravity operating on any slope that can potentially fail (give way)
What is mass wasting primarily driven by?
Mass wasting is driven primarily by gravity
what is a rock falls?
rock is freefalling from a cliff face
◼ Bedrock falls rapidly downward, fragmenting as it impacts
what is creep?
slow downhill movement
due to seasonal soil
expansion and contraction
what are slumps
Slumping: sliding of regolith as coherent blocks
what is a debris flow?
A debris flow is a mudflow with a lot of rocks and debris
what is a mud flow?
slurry of mud and water
what is a lahar?
Volcanic ash from recent or
ongoing eruptions mixes with water from heavy rains or melted glacial ice
