Evidence for Continental Drift and Plate Tectonics

Hazard = occur when and where human and physical systems meet

Basic Structure of the Earth

Mohorovicic Discontinuity marks the Mantle-Crust boundary (continental crust 35km below, oceanic crust 10-15km below surface

lithosphere and crust make up oceanic and continental crusts

The mantle has two layers: the asthenosphere and the lithosphere

Lithosphere:

• rigid layer between crust and asthenosphere
• varies in thickness
• bourdary with asthenosphere…