Layers of the Earth and Tectonic Plates

Warm up  A _________ is a group of living things that are closely related and can produce offspring together. –A. community –B. ecosystem –C. species –D. abiotic factor

Structure of the Earth  The Earth is made up of 3 main layers: –Core  Inner core- –hot, solid metals  Outer core- –liquid metals –Mantle –Crust Mantle Outer core Inner core Crust

The Crust  This is where we live!  The Earth’s crust is made of: –Continental Crust- forms land  thick  - buoyant (less dense than oceanic crust) - mostly old –Oceanic Crust- below the ocean  - thin (~7 km) - dense (sinks under continental crust) - young

Lithosphere and Asthenosphere  Lithosphere- (“litho”- stone/rock)- Earth’s crust and the very top of the mantle –Most rigid layer, sits on top of the asthenosphere, broken into 12 slabs of rock called tectonic plates  Asthenoshpere- (“asthenes”- weak)- layer of hotter, softer rock in the upper mantle

What is Plate Tectonics?  If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle.

Tectonic Plates  Tectonic plates- large, moving pieces of earths’ lithoshpere  Theory of plate tectonics- A theory that states that Earth’s lithosphere is broken into huge plates that move and change over time

Pangaea  Pangaea- “all lands”- one huge supercontinent