Descriptive Astronomy 101
Earth - Erosion


Internal Processes

Processes which create igneous and metamorphic material, and build up landforms on the surface
Tectonics and Plate Tectonics
Magmatism and Volcanism
Isostasy
Core and Mantle Convection
Differentiation

Planetary Erosion

Factors for Planetary Erosion
1)
2)
3)

External Processes

Processes which erode the surface and shape the surface.
Atmospheric composition plays a huge role in determining the type of erosional processes that occur
Critical factors on Earth:

Water World

_______ of Earth's surface is covered by water.
Earth is in an orbital position that is neither too hot, nor too cold.
H2O is naturally found in all three phases.
Where did all of the water originate?
Water easily combines with sulfur, nitrogen oxides, and carbon dioxide to form sulfuric acid, nitric acid and carbonic acid.
Water is an important greenhouse gas.
Water is a natural lubricant.
The addition of water to rock causes the melting temperature and strength of the rock to be decreased.

Oxygen Atmosphere

Oxygen is a very reactive gas.
Oxidation (rusting), combustion
Does not remain in a planetary atmosphere in large quantities unless it is being constantly replaced.
How is oxygen (O2) produced?
1)
2)
3)
4)
5)

Weathering & Erosion

Weathering - The destructive process by which material at or near the Earth's surface are changed in color, texture, composition, firmness or form, with little or no transportation of the altered material
Erosion - The mechanical and chemical destruction of the land (weathering) and the removal of material by moving water, ice or wind

Erosion Processes

Physical Weathering:
Impact, Abrasion, Ice Wedging, Salt-Crystal Growth, Exfoliation, Thermal Expansion, Root Wedging

Chemical Weathering:
Hydration, Hydrolysis, Oxidation, Ion Exchange, Dissolution

Mass Wasting:
Creep, Slump, Landslide, Debris Flow, Mud Flow, Rock Slide, Rock Fall, Avalanche

Surface Processes

Fluvial Processes:
Groundwater Processes:
Eolian Processes:
Glacial Processes:
Coastal Processes:
Impact Processes: