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Earth - Geography

The Earth is composed of a solid inner core, outer core, mantle, asthenosphere, lithosphere, and crust.
Name: Ingredients: Thickness: Temperature:
Inner Core Solid Iron and Nickel 1230 km 4300 C
Outer Core Liquid Iron, Sulfur and Nickel 2250 km 3700 C
Mantle Plastic Magnesium, Iron, Aluminum, Silicon and Oxygen 2500 km 1000 C
Asthenosphere Elastic Mantle 250 km 1600 C
Lithosphere Solid - Brittle Mantle 100 km 1400 C
Crust Oxygen, Silicon, Aluminum, Iron, Calcium, Magnesium, Sodium, Potassium, Titanium, Hydrogen, Phosphorous, and trace elements. Ocean: 8-10km

Continental: 10-70 km

20 C to 1400 C (high temperature not a confident value)

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Convection is the engine driving the motions of the lithosphere and crust.

The Earth is comprised of 14 rigid continental and oceanic tectonic plates:

Major Plates: Minor Plates:
African Plate
Eurasian Plate
Australia Plate
Pacific Plate
Antarctic Plate
Nazca Plate
North American Plate
South American Plate
Philippine Plate
Cocos Plate
Caribbean Plate
Scotia Plate
Arabian Plate
Indian Plate

These plates "float" on an "ocean" of hot magma called the asthenosphere. Each plate contains a layer of crust and a layer between the crust and asthenosphere called the lithosphere.

This is an example of a converging continental plate with another continental plate. This motion is responsible for mountain formation.
This is an example of a converging ocean plate with a continental plate. The crust layer of an ocean plate is much thinner than its continental counterpart, so magma from the asthenosphere can penetrate.
This is an example of two converging ocean plates. This is the type of convergence that resulted in the 9.0 Indonesian earthquake resulting in the tsunami.

The only ocean only plate is the Pacific Plate. Because of the ocean-continental interactions resulting in potential volcanism, the area surrounding the Pacific Plate is called the Ring of Fire.

Interactions between these plates result in sea floor spreading, earthquakes, volcanoes and mountain formation.

There are 5 types of tectonic movement: mid-ocean ridge, oceanic plate meeting (example - Mt. Pinatubo), diving plates (example - Andean Mountains), sliding plates (example - San Andreas Fault), and colliding plates (example - The Alps).

The shifting of these plates is such that there are 7 major periods of continental drift:

Cambrian Period 570 to 510 million years ago
Devonian Period 508 to 362 million years ago
Carboniferous Period 362 to 270 million years ago
Triasic Period 245 to 208 million years ago
Jurassic Period 208 to 145 million years ago
Cretaceous Period 145 - 65 million years ago
Tertiary Period 65 to 2 million years ago

There are three main categories of rock: igneous rocks, sedimentary rocks and metamorphic rocks.

There are several methods of land shaping: coastal waters, ground water, rivers, meanders, deltas, drainage basins, and gullies.

There are 5 major oceans: the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean, and the Arctic Ocean.

There are 12 biographical regions:

Biome: Characteristic: Example:
The Polar Regions Permanent Ice Caps Antarctica
Tundra Desolate Regions - Long Winters and Short Summers Siberia
Needle-Leaf Forest Mild Summers Northern Canada
Broad-Leaf Forest Northern Hemisphere - Seasonal Variations Eastern North America, Japan
Temperate Rain Forest Warm Climate - Wet Summers Southeast Asia
Desert Very Dry - Little Rain Yuma, Arizona
Mediterranean Hot and Dry Summers - Short Winters Spain, Italy
Tropical and Temperate Grasslands Large Regions - Seasonal Rains with Alternate Droughts Argentina
Dry Woodlands Dry Trees and Shrubs South Africa
Tropical Rain Forest Year Around Warm Weather - Large Quantities of Rain Belize
Mountains Vegetation Varieties The Rocky Mountains
Wetlands Tidal Flats, Marshes and Swamps - High Humidity Florida

There are 8 types of natural hazards (with an associated website):

Earthquakes Earthquake Hazard Program
Floods USGS Water Watch
Geomagnetism National Geomagnetism Program
Seismic Activity Global Seismic Network
Hurricanes and Extreme Storms Hurricane and Extreme Storm Impact Study
Landslides and Mudflows Landslide Hazards
Tsunamis Tsunamis and Earthquake Research and What is a tsunami?
Volcanoes Volcano Hazard Program

The total population of Earth is around 5.5 billion people divided into 6 continental categories:

North America Varied Settlements
Europe Dense Settlements
South America Increasing Settlements
Africa Sparse Settlements
Asia 60% of World's Population
Australia and Oceana Sparse Settlements

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