ERTH 2415 Lecture Notes - Lecture 4: Mid-Ocean Ridge, Continental Crust, Oceanic Crust
19 Jan 2017
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Document Summary
Earthquake epicenters and active volcanos do not occur at random. They occur long the edges of the tectonic plates. Differentiation: process by which gravity causes denser material to gradually migrate to the center of the planet. Most dense earth is at the core of the earth. Outer layer: crust (lighter elements, silicon and oxygen: ottawa"s earth crust is 35-40 kilometers. Mattel layer: made of material a little more dense (magnesium and iron) Outer and inner core layers are mostly iron. Buoyancy: earth can be described as a series of layers where less dense material floats to the top of denser material. Ex: ice burgs are less dense therefore causing them to float in the ocean. Rigid lithosphere: what we are currently walking on. Plastic asthenosphere: plastic solid similar to play-doh. Plastic mesosphere: more viscous then the asthenosphere. Comparable to a convections oven circulating the hot air.
