GEO 1401 Lecture Notes - Lecture 8: Low Frequency, Mercalli Intensity Scale, Earthquake Prediction
4 Apr 2016
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Document Summary
Superconinent: pangea, began breaking apart 200 million years ago. Evidence used to support: fit of the coninents, fossil evidence, rock type and structural similariies, paleo climaic evidence. Lack of evidence for a mechanism for moving coninents. Mechanism for movement of coninents: convecion cells located in the asthenosphere and upper mantle that are breaking, sliding, or crashing. Consolidaion of basalt: coninental-coninental: form valley rits and linear seas, oceanic-oceanic: form oceanic rits and new ocean loor. Meling of basalt: oceanic-coninental: subducion oceanic trenches, coninental volcanic arcs. Example: andes mountains: oceanic-oceanic: subducion oceanic trenches, island arcs (volcanism) Most join two segments of a mor along breaks in oceanic crust known as fracture zones. Fault: rupture occurring in the crust (shallow) or lithosphere (deep) Hot spots (mantle plumes): hot column of rock in the earth"s mantle that does not move; it can from isolated volcanoes and are not typically located on a lithospheric plate boundary.
