Plate Tectonics Composition of Earth

Chemical Layers of Earth

Two Types of Crust Oceanic 5-10 km dense rock basalt common Continental 30-50 km lighter rock granite common Oceanic 3-6 mi deep 30-50 km -> 20-30mi

How thin is thin? Earth is about 40,000 km circumference In kilometers 10km = 6 mi. If Earth was a basketball, the crust would be a single sheet of paper. Earth is about 40,000 km circumference

Mantle ~600 to 3000 km Slow circulation – convection currents!

Outer Core ~3000 to 5200 km iron and nickel low viscosity (liquid) http://crack.seismo.unr.edu/ftp/pub/louie/class/100/interior.html

Inner Core ~5200 km solid ball massive pressure mostly iron http://www.ucl.ac.uk/EarthSci/people/lidunka/papers/55.pdf

Physical layers of Earth Lithosphere Asthenosphere Mesosphere Outer core Inner core

What’s the lithosphere? the rigid, outermost shell it is the crust AND the upper portion of the mantle that is hard broken into tectonic plates brittle

Mesosphere higher pressure causes denser, more rigid structure (Not to be confused with atmospheric mesosphere layer!)

And the asthenosphere? deeper, weaker, and hotter than lithosphere part of the upper mantle asthenosphere rock is ductile (deforms like softer plastic) viscous Viscous: Having a thick, sticky consistency between solid and liquid

What did you learn? How are the layers different in temperature, pressure, and composition? http://www.trunity.net/envsciClone/articles/view/177019/?topic=81573