EARTHSC 2GG3 Lecture Notes - Lecture 2: Continental Crust, Oceanic Crust, Plate Tectonics
17 Feb 2017
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Document Summary
Plate tectonics - slow process that moves plates on earth surface causing interactions (earthquakes) producing new ocean topography (reducing and expanding) 2 ways: by composition, state, density, by strength. Tb diagram: relationship between plates: subduction plates that takes parts of continental crust, this creates earthquakes on the west coast, this can produce mega thrust earthquakes - oceanic plate gets hung up and stuck with continental crust. Finallly gives way and produces earthquake and has potential to create large tsunamis. Basic structure of the earth : inner core, outer core, mantle asthetosphere (with more components) and crust on top. Lithosphere: cool, strong outermost layer of earth. Continents and ocean basisn: crustal rocks are less . Continental crus is less dense than oceanic. Oceanic crust is relatively thinner: oceanic crust underlying todays ocean basisns is less than 200 million years old, during production and destruction of ocean basins we are reproducing oceanic crusts. Convection: the less dense magma rises.
