EARTHSC 2GG3 Lecture Notes - Lecture 2: Cascadia Subduction Zone, 1857 Fort Tejon Earthquake, East African Rift
1 Oct 2016
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Document Summary
The big picture: pieces of earth"s surface move around, grind sideways, collide, sink into earth"s hot interior, collisions create mountain ranges, cause tsunamis, less directly, mountain ranges affect weather and climate. Continental crust: the continental crust is silica-rich, has a low density of 2. 7 g/cm. , and is 30-50 km thick: it stands higher than the denser oceanic crust. Oceanic crust: the oceanic crust is iron-rich, magnesium-rich, and silica-poor, with a higher density of 3. 0. 3 g/cm: it is 7 km thick and floats lower than the continental crust, on top of denser mantle. 3 g/cm relative to liquid water at 1. 0 g/cm. 3: thus, 90% of an ice cube or iceberg will be underwater, similarly, for many large mountain ranges, approximately 84% of a mountain range of continental rocks (2. 7 g/cm. ) will submerge into the mantle (3. 2 g/cm.
