• 1. The earth is the only living planet…

* Continents – landmasses above water on earth

IV. External Forces Shaping IV. External Forces Shaping the Earththe Earth

a. Weathering and erosion alter the surface of the earth

WeatheringWeathering

WeatheringWeathering

• physical and chemical processes that change the characteristics of rock on or near the earth’s surface

v. Mechanical Weathering – processes that break rock into smaller pieces (doesn’t change the composition of rock, but the size)

*Sediment - Small pieces of rock created by mechanical weathering (mud, sand or silt)

Examples of Mechanical Weathering

Camel Rock - Santa Fe, NMCamel Rock - Santa Fe, NMExample of Mechanical WeatheringExample of Mechanical Weathering

© Jon Benignus, 2011

Wind and Water Erosion

vi. Chemical Weathering – occurs when rock is changed into a new substance as a result of interaction between elements in the air or water and minerals

(example – iron rusting)

Why are the rocks red?

Erosion-movement of Erosion-movement of weathered materialweathered material

ii. Erosionii. ErosionOccurs when

weathered material is moved by the action of wind, water, ice and gravity

Erosion is transporting sediment

• 2. Water, wind, and glaciers cause erosion…

http://www.wwnorton.com/college/geo/animations/glacial_advance_retreat.htm

wind erosionwind erosion

Loess – windblown silt and clay sediment that produces very fertile soil

Water ErosionWater Erosion

• Delta – sediment is deposited in a fan-like landform when a river enters an ocean

Glacial ErosionGlacial Erosion• Glacier – a large, long-lasting

mass of ice that moves because of gravity

• Glaciation – changing of landforms by slowly moving glaciers,

• Moraine – rocks left behind from a glacier that form a ridge or hill

GlacierGlacier

MoraineMoraine

V. Distribution of Physical Features V. Distribution of Physical Features on Earth: on Earth:• How do plate

tectonics, weathering and erosion affect the location & distribution of physical features?

• a. For the Ring of Fire, the location is due to being where the crust of the earth is very thin. This is the primary factor, plate tectonics, not climate.

• b. For the Great Plains, climate & type of soil are the primary factors in the location of this region.

• c. The climate of the Great Plains is Humid Continental, Semiarid and Humid Subtropical.

• The type of soil is a major factor, in the Ring of Fire .Volcanic soil can be very fertile, as well as the soil in the Great Plains.

• Tropical Rainforest are located between the 23 ½ N Tropic of Cancer & 23 ½ Tropic of Capricorn, causes these areas to be quite warm and to have a lot of rain.