EARTHSC 2GG3 Lecture Notes - Lecture 3: San Andreas Fault, Convergent Boundary, Seafloor Spreading
17 Feb 2017
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Document Summary
Seismic activity focused at plate boundaries: with some anomalies. At the edges of plate is where crusts are destroyed. Size of earth isnt getting bigger so something must be taken away. Earthquakes occur along path of descending plate. Convection in the interior of earth is driving force behind plate motion. Molten magma that gets convected and drives motion. Transform: 2 plates slide pass each other. Falls: drop down and get so low can get ocean water flows through. Spreading can continue and can form ridges - grow ocean basin and continue to grow and produce more oceanic crust - divergent situation. Where 2 plates move away from one another. Where edges of 2 plates slide horizontally past one another. Not a lot of up and down motion but back and forth. Mid ocean ridges were areas of sea floor spreading - hess. When volcanic rocs (rich in iron) when they cool record their polarity.
