Erosion and Deposition
SPA Grade 6 Focus on Earth Science Chapter 8 Flashcards
Terms in this set (46)
What is erosion?
The process by which natural forces move weathered rock and soil from one place tom another.
What is sediment?
Sediment is the material moved by erosion
What is deposition?
Occurs where agents of erosion lay down sediment.
What works in a cycle to wear down and build up Earth's surface?
Weathering, erosion, and deposition
What is gravity?
The force that moves rock and other materials downhill.
What is mass movement?
Any of several processes that move sediment downhill at varying speeds.
What are landslides and how do they occur?
The most destructive kind of mass movement which occurs when rock and soil slide quickly down a steep slope (most contain only a small amount of rock and soil).
What is a mudflow?
A mudflow is the rapid downhill movement of a mixture of water, rock and soil.
Other facts about mudflows.
The amount of water can be as high as 60%
Often occur after heavy rain in dry areas
Clay soils often trigger mudflows
Earthquakes can also trigger mudflows.
What is slump?
When a mass of rock and soil suddenly slips down a slope. Unlike a landslide it moves in one large mass.
What is creep?
The very slow downhill movement of rock and soil. Often tilts objects.
What is the largest agent of erosion?
What is runoff?
All the remaining water that moves over Earth's surface after rain and can cause sheet erosion if flowing in a thin layer over land
What is a rill?
Tiny groove in soil.
What is a gully?
A large groove or channel that carries runoff after a rainstorm.
What is a stream?
A channel along which water is continually flowing down a slope.
What is a river?
A large stream.
What are the five main factors of runoff?
Amount of rain
Type of Soil
Shape of Land
Use by people
What does more runoff mean?
What is a tributary?
A stream that flows into a larger stream.
What is a drainage basin?
the land area from which a river and its tributaries collect water.
What is a divide?
the high ground between two drainage basins.
What do rivers create?
Waterfalls, rapids, V-shaped valleys, meanders, oxbow lakes, valley widening, alluvial fans, deltas, floodplains, and beaches.
What is an alluvial fan?
A wide sloping deposit of sediment formed where a stream leaves a mountain.
What is a delta?
sediment deposited where a river flows into a still body of water.
What is groundwater?
What is a stalactite and stalagmite?
A deposit hanging from the roof of a cave
Cone shaped deposit on the cave floor.
What is a rock formed underground?
What is karst topography?
A type of landscape over a layer of limestone.
What is a characteristic of karst topography?
What is energy?
the ability to do work or cause change
What is potential energy?
Potential energy is energy that is being stored and waiting to be used later
Kinetic energy is?
the energy an object has due to motion
What happens as gravity pulls water down a slope?
Potential energy changes to kinetic energy which can do work.
What happens when sediment enter streams or rivers?
Sediment washes or falls into the river while other sediment erodes from the sides or bottom of the river.
What is abrasion?
The wearing away rock by a grinding action.
What is a rivers load?
The amount of sediment it carries.
What are the factors of how fast the river flows and how much sediment can erode and how does each affect the river?
Slope-if the slope increases so does the water's speed
Volume of flow- As more water flows through, the speed increases
Streambed Shape-Deeper streambeds slow speed and vice versa
What is friction?
The force that opposes the motion of one surface as it moves across another.
What is turbulence?
Turbulence is a type of movement that adheres motion
Name two of four types of mass movement
Landslides, slump, creep or mudflows
what are a few things that creep affects?
Trees, telephone poles, fences, streets, and gravestones
How is a kettle lake formed?
When a depression, created by melting ice, is left in the till and fills
What is a moraine?
A ridge formed by the till deposited at the edge of a glacier
What is plucking?
As a glacier flows over the land it picks up and moves rock
What are the two processes in which glaciers erode land?