EOSC 114 Chapter Notes - Chapter Ch 3: Magnetization, Epicenter, Continental Drift
22 Mar 2016
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Document Summary
Movement of tectonic plates cause earthquakes, erupions, and mountains. Earthquakes and erupions mostly along edge of plates where lithospheric stresses are concentrated. Plate tectonics: study of movements and interacions of plates. Asthenosphere lows upward as magma cools and forms new lithosphere on ocean loor. Lithosphere slowly moves laterally away from zone of oceanic crust formaion. It glides on top of asthenosphere and carries low-density coninents like on a conveyor belt. When leading edge of moving plate of oceanic lithosphere collides with another plate, the denser one moves down and is pulled by gravity back into asthenosphere (subducion) and the less dense overrides it. Plate pulled into asthenosphere is reabsorbed. ((this cycle takes a long ime: ~250 mil years)) Upper few hundred km of earth is constantly being recycled according to tectonic cycle with the asthenosphere being the main driving force of plate movement. 4 tectonic environments: divergent zones, convergent zones, transform plate boundaries, and hot spots.
