The Geosphere What is the GEOSPHERE All solid

The Geosphere

What is the GEOSPHERE? • All solid parts of Earth – Rocks, soils, minerals, sediments, magma The Grand Canyon, AZ

Remember… Cru. Man. Co Chemical Company

Layers of the Earth • Geologists classify Earth’s layers two ways: chemically and physically • Chemical – by composition • Physical- by structure Chemical Layers of the Earth 1. Crust- O, Si, Al 2. Mantle- O, Si, Mg, Fe 3. Core- Fe, Ni

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=Q 9 j 1 x. Gax Yz. Y 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- separating 2. Convergent- colliding 3. Transform- scraping past

Tectonic Plates Active Volcanoes Earthquakes Worldwide

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 Boundaries Three 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 1. trench 2. 3. Continental & Continental- causes 3. large land mountain ranges 4. Ex: Himalayan Mountains

Subduction Zone Continental + Oceanic Crust

Subduction Zone Oceanic + 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=ryr. XAGY 1 dm. E&feature=endscreen&NR=1 San Andreas Fault: • http: //www. youtube. com/watch? NR=1&v=Zx PTLmg 0 ZCw&feature=endscreen