Unit 4 Ls. 1 Definitions

Question 1

Crust

Answer 1

the outermost layer of rock of which a planet consists, especially the part of the earth above the mantle

Question 2

Mantle

Answer 2

the region of the earth’s interior between the crust and the core, believed to consist of hot, dense silicate rocks

Question 3

Core

Answer 3

The outer core of the Earth is a liquid layer about 2,260 kilometers thick

Question 4

Convection

Answer 4

the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity

Question 5

Lithosphere

Answer 5

the rigid outer part of the earth, consisting of the crust and upper mantle

Question 6

Asthenosphere

Answer 6

the upper layer of the earth’s mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur

Question 7

Mesosphere

Answer 7

the region of the earth’s atmosphere above the stratosphere and below the thermosphere, between about 30 and 50 miles in altitude