Earth's Surface (Part 1)

Definitions and Concepts Related to Earth's Surface

Key Terms

• Discharge

  • Definition: The quantity of water in a stream that passes a given point in a period of time.

• Erosion

  • Definition: The process by which sediment and other materials are moved from one place to another.

• Deposition

  • Definition: The process by which eroded material is dropped.

• Weathering

  • Definition: The process by which rock is broken down into smaller pieces by either physical or chemical means.

• Gradient

  • Definition: The measure of the change in elevation over a certain distance.

• Elevation

  • Definition: The height of land above sea level.

• Load

  • Definition: The amount of sediment that a river or stream carries.

• Canyon/Valley

  • Description: Formed by erosion, caused by a stream or river.

• Meander

  • Description: A location of a stream or river where the bending or curve causes material to be eroded.

• Point Bar

  • Description: A crescent-shaped accumulation of sand and gravel deposited on the inside of a meander.

• Floodplain

  • Description: An area along a river that forms from sediments deposited when the river overflows its banks.

• Alluvial Fan

  • Description: A process that occurs when a stream flows onto a flat land surface from a mountain or hill, creating a fan-shaped deposit on dry land.

• Groundwater

  • Definition: Water that fills the cracks and spaces in underground soil and rock layers.

• Shoreline

  • Definition: The place where land and a body of water meet.

• Headlands

  • Description: Points of high land that stick out into a body of water.

Coastal Features

• Beach

  • Description: An area of the shoreline that is made up of deposited sediment.

• Dune

  • Description: A mound of wind-deposited sand that moves as a result of the action of wind.

• Loess

  • Description: Fine-grained sediments of quartz, feldspar, hornblende, mica, and clay deposited by wind.

Glacial Features

• Glacier

  • Definition: A large mass of ice that exists year-round and moves over land.

• Glacial Drift

  • Definition: The rock material carried and deposited by glaciers.

Geological Processes

• Creep

  • Description: The slow downhill movement of weathered rock material.

• Landslide

  • Description: The sudden movement of rock and soil down a slope.

• Mudflow

  • Definition: The flow of a mass of mud or rock and soil mixed with a large amount of water.

Forces of Change

• Deconstructive Forces

  • Description: Forces that shape the Earth's surface by tearing down or destroying landmasses, destroying the crust.

• Constructive Forces

  • Description: Forces that shape Earth's surface by building mountains and landmasses.

• Delta

  • Description: A triangular area of marshland formed by deposits of silt at the mouth of some rivers.