EXTERNAL GEOLOGICAL PROCESSES

EXTERNAL GEOLOGICAL PROCESSES

1. ICE

   • Types of glacier
     • Alphine
       • Found in mountain ranges at high elevations. Confined by the mountain valleys that surround them.
     • Continental
       • Found in polar regions,not confined by topography
   • Definition of
     • Glacier
       • Thick mass of ice that moves over the land
     • Iceberg
       • Large piece of ice that has broken off a glacier and fallen into lake or sea
   • 2 erosion processes
     • Plucking
       • Material pulled out from the bed and walls of the glacial valley
     • Abrasion
       • Rock fragments stuck in the ice cut the walls and the floor of the glacial valley
   • Glaciar Landforms
     • Horn
     • Arète
     • U-shaped valley
     • Hanging valley
     • Lake
   • Deposital landsform
     • Moraine
       • Depending on the position
         • Lateral
           • At the end
         • Lateral
           • At the side
         • Medial
           • In the middle

2. Wind

   • Two conditions for erosion
     • Presence of loose material
     • Absence of vegetation
   • Erosional landform
     • Mushroom rocks
       • The wind abrasion is more in the ground, turn isolated boulders into mushroom rocks
     • Honeycombs
       • Is created when low density or heterogeneous rock is expsed to the impact of sand carried by the wind, this create small hollows in the rock
     • Desert pavement
       • Is caused by the sweeping effect of deflation onthe desert surface, small and medium partcles are removed
   • Definitios of...
     • Deflactions
       • The wind detaches and removes loose particles from the surface of the Earth
     • Abrasion
       • The material transported by the wind crashes into rocks. The impact and friction of this material on rocks polishes and wears away them
   • Depositial landforms
     • Dune
       • Is a mound of sand that has been transported by the wind. This landforms are continually changing
     • Loess
       • Is an extensive deposit of fine-grained particulate matter such as silt, from dust sorms. The wind often deposits this material, and deposits enrich the quality of the soil.

3. SEA

   • Two water movements causing EROSION
     • Waves. Are caused by the action of the wind on the surface of the water
     • Tides. Are oscillations in the sea level
   • Landforms caused by erosion
     • Headlands and bays
     • Natural bridges
     • Wave-cut platforms
     • Cliffs
     • Seastacks
   • 2 methods for transportof eroded material
     • Waves. Drag materialin toward the beach and then back out again, to make particles rounderand smaller
     • Longshore drift. When the direction of the wind and the waves causes the sea water to transport material, pulling it along the coastline
   • Landsform caused by deposition
     • Lagoons
     • Spits
     • Deltas
     • Tombolos
     • Marshes
     • Beachs
     • Sandbars