The Geosphere

What is the GEOSPHERE?

• All solid parts of Earth– Rocks, soils, minerals, sediments, magma

The Grand Canyon, AZ

Remember…

CruManCoChemical Company

Layers of the Earth

1. Crust- O, Si, Al 2. Mantle- O, Si, Mg, Fe3. Core- Fe, Ni

• Geologists classify Earth’s layers two ways: chemically and physically• Chemical – by composition• Physical- by structure

Chemical Layers of the Earth

Physical Layers of the Earth

• Lithosphere– Crust and upper mantle combined– Broken in chunks called tectonic plates– Oceanic plates are thinner and denser than

continental plates• Asthenosphere

- Layer of Jello-like magma in the mantle- Tectonic plates move due to convection

currents in the asthenosphere

Physical Layers, cont.

• Mesosphere– The rest of the mantle;

molten rock• Outer Core

– Liquid metal– Surrounds inner core

• Inner Core– Densest layer– Solid metal

Remember…

LAMOI,The physical trainer

• http://www.youtube.com/watch?v=Q9j1xGaxYzY

earth layer song

Theory of Plate Tectonics

• Lithosphere (upper mantle and crust) is divided into pieces called tectonic plates.

• These plates glide across the underlying asthenosphere like ice drifts across a pond.

• Continents are located on tectonic plates and move around with them

Plate Boundaries• The area where two plates meet is called a

plate boundary.• Most earthquakes and volcanoes occur at or

near plate boundaries

Three main types of plate boundaries:1.Divergent- separating2.Convergent- colliding3.Transform- scraping past

Earthquakes Worldwide

Tectonic Plates

Active Volcanoes

Transform Boundaries• 2 plates slide past each other

• This sliding is not smooth. Plates lock and build up tension. After too much tension builds, the plates “snap” and move against each.

• Causes earthquakes

Divergent Boundaries

• When two plates separate

• Most common on ocean floor

• Creates Mid-Atlantic Ridge which is visible on land in Iceland

Divergence Forms New Ocean Floor

Convergent BoundariesThree Main Types:

1.Continental & Oceanic- causes deep ocean trench and land volcanoes Ex: Andes Mountains

2. Oceanic & Oceanic- causes deep ocean trench and island arc (chain of volcanic mountains) Ex: Mariana islands and Mariana trench

3. Continental & Continental- causes large land mountain ranges Ex: Himalayan Mountains

Subduction Zone Continental + Oceanic Crust

Subduction ZoneOceanic + Oceanic Crust

Subduction Zone Oceanic + Oceanic Crust (another view)

Continental + Continental Crust

Some videos for your viewing pleasure…

Plate Movement:•http://www.youtube.com/watch?v=ryrXAGY1dmE&feature=endscreen&NR=1San Andreas Fault:•http://www.youtube.com/watch?NR=1&v=ZxPTLmg0ZCw&feature=endscreen