4-1 Mass Movement
What is the process by which weathered rock, sediment, and soil are moved from place to place?
Erosion
Which feature typically contains water only during a rainstorm and right after it rains?
Gullies
What do you call a mass of rock and soil deposited directly by a glacier?
A till
What is a rocky part of the shore that sticks out in the ocean called?
A headland
What do you call the erosion of sediment by wind?
Deflation
Freezing and thawing of water can cause creep, which is _______.
Freezing and thawing of water can cause creep, which is a very slow downhill movement of rock and soil.
How are oxbow lakes formed? (these are the ones that look like horseshoes
Sometimes a meandering river curves so much that it curves into itself. The meander gets cut off from the new path of the stream and forms an oxbow lake.
The process where glaciers flow over the land and pick up rocks is called _______
The process where glaciers flow over the land and pick up rocks is called plucking
Waves change directions as they near shore because _________
Waves change directions as they near shore because different parts of the wave drag on the bottom of the shore.
What is loess?
Very fine sediment, made up of tiny particles of silt and clay. Wind can pick it up and deposit it very far away. The land where it gets deposited is usually very fertile as a result.
How are landslides and mudflows similar? How are they different?
Both are types of mass movement that occur rapidly. Landslides are mostly dry and mudflows include water.
How are waterfalls formed?
When a river flows over an area of rock that is very hard, that area erodes more slowly. When it flows over softer rock later, this softer rock erodes more quickly than the harder rock.
How are U-shaped valleys formed?
As glaciers are pulled downward by gravity, they can pluck rocks and erode the land beneath them. When the glacier melts, a U-shaped valley is left behind.
Under what weather conditions would you expect abrasion to cause the most erosion on a beach?
During a storm, when the waves are stronger and more frequent.
How do sand dunes form?
As rocks erode and forms sand, wind picks up and move that sand. When the wind meets an obstacle it deposits that sand, which can eventually grow to form a sand dune.
Identify the steps in the erosion cycle. Explain why it has no beginning and end. (Think about what happens with erosion and deposition)
Erosion wears down land and deposition fills up hollows. New mountains or plateaus form, which are eroded. It's continuous because the forces of erosion and deposition don't stop.
Your family is looking to buy a new house right on the bank of a river. Why might they hesitate to buy this house?
The house might be in the rivers flood plain and could be damaged by the flood, OR the banks of the river could erode over time and the rive could eventually reach the house and damage it.
How and where do glaciers form?
Glaciers form in areas where snow falls more than it melts. As snow falls more and more, it gets pressed into ice crystals by all of the snow on top of it. As this ice grows larger, it can become a glacier.
Explain how a sea arch or sea stack forms.
Sea arches form when a headland made of harder rock resists erosion from the waves and begins to stick out into the ocean. If there are softer areas of rock underneath the harder rock on a headland, it will erode faster and form a sea arch. If an arch erodes so much that it collapses, it becomes a sea stack.
How is deflation different from wind erosion?
Deflation causes most wind erosion by removing surface materials. Abrasion polishes surface material but doesn't move much.