The Impact of Water, Wind, and Ice on Landforms
Geological Agents: Shaping Earth’s Surface
GAERC: Surface Water and Groundwater
Surface water and groundwater are influenced by wind, sea, and ice.
Weathering
Weathering occurs when rocks are broken down into relatively large pieces.
Erosion
Erosion is the wearing away of rocks.
Transportation
Eroded materials are transported to other locations.
Sedimentation
Transported materials are deposited in sedimentary basins.
Surface Water
Surface water originates from rainfall or snowmelt that seeps into the ground.
Runoff
Runoff is water that forms when rain falls heavily on sloping and deforested land, creating formations like gullies and fairy chimneys.
Torrents
Torrents emerge in runoff areas with steep slopes, forming ravines.
Ramblas
Ramblas are wadis formed by sporadic rainfall.
Rivers
Rivers are continuous flows of water arising from the union of various water streams. The quantity of water is called river flow and can vary throughout the year.
Upper Course
Located in mountainous areas, the upper course is where major rivers originate. The flow speed and gauges are high.
Middle Course
The slope slows down the water, but the river’s flow increases with the input of other water courses called tributaries.
Tributary
A tributary is a river that flows into another river.
Meander
A meander is a curve in the river where the water on the outside flows faster, causing erosion, while the water on the inside flows slower.
Lower Course
The lower course corresponds to the mouth of rivers in the oceans. The river flows through shallow areas with a wide bed.
Delta
Deltas occur when rivers carry a large amount of material that is deposited at the bottom, forming islands or arms of sediment.
Estuary
An estuary appears when rivers flow into open seas with large tides and profound depths.
Karstic Landforms
Karstic landforms are soils formed in water-soluble rock faces that experience serious weathering when exposed to water.
Lapiaz or Lapiés
Lapiaz are furrows formed by water runoff.
Zone of Saturation
The zone of saturation is the area of land whose pores are fully saturated with water.
Aeration Zone
The aeration zone is the area between the surface and the zone of saturation.
Water Table
The water table is the upper limit of the saturated zone of an aquifer.
Dolina or Sinkhole
Dolines are circular depressions that may or may not be filled with water.
Shafts (Simas)
Shafts are vertical conduits that can communicate abroad.
Gallery
A gallery is a horizontal canal that can be transformed into rooms when its size is large.
Caves and Caverns
Caves and caverns are galleries that communicate with the outside.
Stalactite
Stalactites are conical formations on the roofs of caves.
Stalagmite
Stalagmites are formed when water drops falling from the roofs deposit calcium carbonate on the ground.
Columns
Columns appear when stalactites and stalagmites join together.
Aquifers
Aquifers are formed when infiltrating water fills all the holes in the ground and accumulates beyond a certain level.
Ice (Glaciers)
Glaciers are masses of ice in movement, covering 10% of the Earth’s surface.
Ice Sheets
Ice sheets are large tracts of land covered in the polar zone.
Alpine Glaciers
Alpine glaciers are located in high mountains.
Glacial Cirque
A glacial cirque is an area where snow accumulates from precipitation.
Glacial Tongue
A glacial tongue is a mass of ice that flows through the valley.
Glacial Front
The glacial front is the area where ice melts and deposits glacial materials.
Glaciers
Glaciers are masses of ice in movement.
Wind Action
Wind produces the action of deflating the rock.
Deflation
Deflation is when the wind carries smaller particles (dust) and keeps them in suspension. Slightly larger particles (sand) are transported by saltation or drag, and the largest particles roll.
Aeolian Abrasion
Aeolian abrasion is produced by the shock of particles carried in suspension by the wind on the rocks.
Rocky Desert
In a rocky desert, the wind has carried away the finest materials, leaving only sand and broken rock.
Sandy Desert
In a sandy desert, fine materials are carried away and accumulate by the wind, forming dunes.
Sea Action
Sea water has a triple action and transports sediments.
Swell
Swell depends on the intensity of the wind.
Tides
Tides produce two daily low and high tides.
Currents
Currents are caused by the action of surface wind or surges caused by differences in water temperature.
Erosive Processes
Erosive processes are intense in mountainous coastal regions.
Beach
Beaches are formed on coasts where gravel and shells are deposited by wave action.
Tombolo
A tombolo is formed by sand accumulations that join islands to the coast.
Littoral Barrier
A littoral barrier is an accumulation of sand along the coast.
Spit
A spit is a coastal barrier connected to the coast.
Albufera (Coastal Lagoon)
An albufera occurs when two spits join, forming coastal lagoons.
Marshes
Marshes are formed by the accumulation of materials at the mouth of rivers.