Structure of Earth

Earh's Sphere's: 4 main parts of Earth
- Luthosphere: Land, rocks, minerals
- Atmohsphere: Air, gasses, vapours
-Hydrosphere: All forms of water
- Biosphere: Living Organisms, Life

Layers of Earth:
Crust: Surface of earth, thinnest layer, cold solid, broken into tectonic plates.
Mantle, hot, made of liquid magma, contains covection currents
Outer core: Hot, made up of liquid nickle and iron. Together with the inner core, is is the thickest layer.
Inner core: Hottest Layer, made of solid nickle and iron.
* Convection currents: Movement of energy from one place to another. Makes tectonic plates move.

Theory of Plate Tectonics:
- Earth's curst is broken into plates
- Convection currents in upper mantle cause plates to move

Plates can:

Diverge:
- Plates spread apart
-Oceanic Ridge: When sea floor spreads apart, Rift valley: caused by plates moving apart on land.
Ex. Mid -Atalantic ridge, frica's rift valley

Converge:
- When plates collide
- Moutnains are formes Ex. Himalayas
- Subduction: When an oceanic plate collides with a contienetal plate and slides beneath it.
- Creates volcanoes, earthwuakes, and deep-sea trenches

Transform: Transformation
-Plates slide past each other, grnding gainst eachother as they move
- Creates Earthquakes. Earthquakes happen when 2 plates that haven't moved in years, suddnly slide again eachother. Magnitue o earthquakes is measure on the Richter Scale.

Ring of fire: contains 75% of active volcanoe's, 90 of world's earthquakes, and 8-% of the world's largets earthquakes
Tsunamis: Long Ocean Waves formed when water is displaced by under water earthquakes/volcanic erruptions.

	Created by RP - 09RS 791730 Castlebrooke SS about 1 year ago

Grade 9 Geography Note on Structure of Earth, Tectonic Plates, and Continental Drifting, created by RP - 09RS 791730 Castlebrooke SS on 16/09/2023.