Key Terms in Geography: A Glossary

A.

  • Abrasion: Erosion caused by the rubbing action of rock fragments carried by rivers, glaciers, etc.
  • Arête: A narrow, knife-edged ridge caused by glacial erosion.
  • Attrition: Material is moved along the bed of the river, collides with other material, and breaks up into smaller pieces.

B.

  • Bar: A barrier of sand stretching across a sheltered bay.
  • Backswash: When water returns down the beach to the sea.

C.

  • Climate: The average weather conditions of a place over many years.
  • Condensation: Gas changes back into water.
  • Confluence: The place where a tributary joins the main river.
  • Corrasion: Fine material rubs against the river bank.
  • Corrie: A rounded hollow caused by glacial erosion.
  • Corrosion: Some rocks forming the banks and bed of a river are dissolved by acid in the water.

D.

  • Delta: An area of silt deposited by a river where it enters the sea or a lake.
  • Depression: An area of low pressure.
  • Destructive margin: A boundary between two plates.
  • Drainage basin (river basin): The area of land drained by a river and its tributaries.

E.

  • Embankment: A raised river bank built to prevent or reduce flooding.
  • Erosion: The wearing away of the land.
  • Evaporation: The transfer of water from the sea to the Earth as water vapor.

F.

  • Flood: The flow of water over an area that is usually dry.
  • Flood plain: The wide, flat area at the bottom of a valley which is often flooded.
  • Freeze-thaw: Rock is broken up due to water in cracks freezing and thawing.

G.

  • Glacial trough: A valley with steep sides, a flat floor, and a U-shaped cross-section carved by a glacier.
  • Glacier: A slow-moving mass of ice flowing down a valley.
  • Groundwater: Water stored underground in permeable rocks.
  • Groyne: A barrier built out into the sea to slow the movement of material along the beach.

H.

  • Hydraulic action: The sheer force of water hitting the banks of the river.
  • Hydrological cycle: The continuous transfer of water from the oceans into the atmosphere.

I.

  • Impermeable: A rock or soil that doesn’t let water pass.

L.

  • Levée: An artificial embankment built to prevent flooding.
  • Longshore drift: The movement of material along a coast by breaking waves.

M.

  • Meander: The winding course of a river.
  • Moraine: Material that is transported and later deposited by a glacier.

P.

  • Plucking: When ice freezes and sticks to the rock.
  • Precipitation: Water falls to Earth either as a liquid or as a solid.

R.

  • Runoff: Most water returns to the sea in the form of rivers.

S.

  • Saltation: Small particles bounced along the bed in a ‘leap-frog’ motion.
  • Suspension: Fine material carried by the river that discolors the water.
  • Swash: The movement of material up a beach after a wave breaks.
  • Silt: Fine soil left behind after a river floods.

T.

  • Terminal moraine: Marks the furthest or maximum point that a glacier reached.
  • Traction: Large rocks and boulders are rolled along the bed of the river.
  • Transpiration: The transfer of water from plants to the air as water vapor.
  • Tributary: A small river that flows into a large river.

W.

  • Water cycle: The continuous transfer of water from the oceans into the atmosphere, then onto the land, and finally back into the oceans.
  • Watershed: The boundary separating two river basins.