Rocks Breaking Down Into Smaller Pieces

Erosion

  Rocks breaking down into smaller pieces

Runoff

  Water that moves over Earth’s surface

  Causes sheet erosion

  Moves downhill

  Forms rills, gullies, streams, rivers, tributaries

  When runoff flows in a thin layer it may cause sheet erosion

  Amount of runoff depends on amount of rain, vegetation in area, type of soil, land shape, and how people use the land

  Increases due to pavement, like parking lots because water cannot be absorbed into asphalt

  Increases due to farming because vegetation (trees, shrubs) is cut down

  Rills- tiny grooves in the soil

  Gully- large groove or channel in the soil that carries runoff

  Tributary-stream or river that flows into a larger river

Rivers

  Erosion creates valleys, waterfalls, flood plains, meanders, oxbow lakes

  Deposition creates alluvial fans, deltas, add soil to flood plain

  Waterfalls wear down softer rock

  Flood plain- flat, wide area of land around river, covered by water when river floods, in places like Egypt flood plains provide fertile soil for growing crops along big rivers like the Nile

  Meander-looplike bend in a river, becomes more and more curved over time

  Oxbow lake- meander that has been cut off from river, can form during flooding

  alluvial fans- wide sloping deposit of sediment where a stream leaves a mountain range

  deltas- sediment deposited when a river enters the ocean, example- Mississippi River creates a delta when it enters the Gulf of Mexico in New Orleans

Groundwater

  Underground water

  Chemical weathering-water sinks into the ground and combines with CO2 to form carbonic acid in a chemical reaction, breaks down limestone

  Forms caves, stalactite (roof) and stalagmite (floor)

Glaciers

  Continental glaciers-covers much of continent, island, like Greenland and Antarctica, ice age is when continental glaciers cover most of the Earth

  Valley glaciers-long, narrow glacier from snow and ice in mountain valley, usually move down valleys that have been cut by rivers

  Glaciers form when more snow falls than melts, snow and ice builds up

  Plucking-picks up rocks as the glacier flows, can crush rocks, can move big boulders

  Breaks rocks

  Drags rocks which scratches bedrock, called abrasion

  Deposits sediment when it melts- till, moraine, kettle

  till- sediments and particles left by a glacier when it melts

  Moraine- till deposited at edge of glacier, forms ridge, Long Island is a moraine

  Kettle-

Waves

  Energy comes from wind blown across water’s surface

  Break apart rocks on shore

  Abrasion-headland, arch, cave

  Deposit sediment-beaches, spits, sandbars, barrier beaches

Wind

  Deflation-wind removes surface materials, Dust Bowl

  Abrasion-Polishes rock, little erosion

  Deposits-sand dunes, loess-sediment that is finer than sand