1. Mass Movements

2. Weathering and Erosion
Order
Weathering
Erosion
Deposition
Weathering breaks down the rocks, erosion moves the particles, and deposition drops the sediments in another location.
Badlands National Park, South Dakota

3. Erosion Erosion – the process where sediments are transported by: Wind
Gravity
Glaciers
Running water
Living Things

4. Mass Movement: Creep
Slow, steady, downhill flow of loose materials – 3 cm/year
Oops!

5. Mass Movement: Slides
Rapid, downslope movement of layer of loose material
Often in areas with steep topography
NOT just due to water!
Ex. landslide

6. Mass Movement: Avalanche
Landslides of snow on steep slopes
Can be very high speeds – 300 km/hr! (200mph)

7. Mass Movement: mudflow
Swiftly moving mixtures of mud and water
Triggered by earthquakes, heat from volcanoes, melting snow, and rainstorms

8. Mass Movement: Slump Landslide along a curved surface
Common after rains along steep slopes

9. Glacial Erosion Glacier: large, moving mass of ice
Cover 10% of Earth’s surface
Great size, weight and density slowly moving grind out bedrock

10. Glacier Formation Form near the poles and at high elevations
Accumulation of snow – increases each year
Weight of top layers exerts downward pressure forcing snow below to re-crystallize into ice

11. If Formed in Valley:
Snow accumulation causes glacier to become heavy and to flow downhill, due to gravity
Speed affected by slope, temperature, thickness of ice and valley shape – 1mm/day

12. Valley Glaciers Carve out U-shaped valleys from bedrock
Change valleys from a V shape to a U shape

13. Valley Glaciers
Cirque - deep depression carved out at the head of a glacial valley.
Moraine - rock piles deposited from melted glaciers

14. Quiz
You can use your rock cycle cheat sheet and this set of notes on your quiz today