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8.1. The spheres of planet Earth

 

8.1.1. Warm up. The spheres of planet Earth.
Match the terms and their general English equivalent.

a)      the air mass that surrounds Earth

b)      the innermost layer of planet Earth

c)      the layer beneath the Earth’s crust

d)     the mass of water on the surface of planet Earth

e)      the outermost rock layer of planet Earth  

f)       the sphere of living organisms

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8.1.2. Complete the table based on what you know about the earth’s structure.

a)      It covers the Earth’s surface, or is covered by oceans

b)      It has a liquid outer part and a solid inner part.

c)      It is 2900 kms thick

d)     It is 35 kms thick under continents

e)      It is 3500 kms thick

f)       It is 6 kms thick under oceans

g)      It is solid

h)      Its outer part is made up of iron and nickel, its inner part is made up of iron.

i)        Its temperature is between 3500 to 5000 degrees Celsius

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"Earth-crust-cutaway-english" by Surachit - Self-made, based on the public domain image File:Earth-crust-cutaway-english.png by Jeremy KempThis vector image was created with Inkscape.. Licensed under CC BY-SA 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Earth-crust-cutaway-english.svg#/media/File:Earth-crust-cutaway-english.svg

8.1.3. The lithosphere and the astenosphere

In geology, a distinction is made between the lithosphere and the astenosphere. The lithosphere is made up of the Earth’s crust and the outermost part of the mantle. It is made up of solid rock, its thickness is between 60 and 150 kms. Under the lithosphere conditions change gradually. Instead of a solid state, rocks are in a so called plastic state. This layer is called the astenosphere. The litoshpere plates float on the top of the astenosphere.