Earth interior

The crust

Crust-is everything above the mantle like oceans,mountains...etc. The crust is a layer of solid rock that includes both dry land and ocean floor. The crust can be anywhere from 5 to 40 feet deep. Some main things the crust is made of is basalt and granite.

Granite is a rock usually is light color and has coarse grains. Basalt is a dark fine grained rock.

The mantle

The mantle is made of rock that is very hot but solid. Scientist divide the mantle into three sections based on physical characteristics. Overall the mantle is nearly 3,000 kilometers deep.


The lithosphere-is the upper part of the mantle that is hard,strong and ridge and averages about 100 kilometers deep.


The asthenosphere-is the middle layer is hotter than the layer above but less ridge. It is solid but can bend like a metal spoon.


The mesosphere-is the last layer in the mantle. This layer is hotter and more ridge then the layer above. This layer is really stiff because of the presser .

The core

The core- is mostly made of metals iron and nickel. It consist of 2 parts the inner core and the other side. The total radius of the core is 3.480 kilometers.


The outer core-is a layer of molten metal surrounding the inner core.


The inner core-is a dense ball of solid metal,extreme presser squeezes the atoms of the iron and nickel so much that it can not spread out to become liquid.

How do geologist learn about the earth interior

Geologist have to use two types of evidence to learn about earths interior which is direct and indirect evidence.


direct/rock samples- Geologist have drilled holes as deep as 12.3 kilometers into earth,the drills bring up samples of rock.These rocks give geologist clues about earths structure and condition deep inside earth.


indirect/seismic waves- To study earths interior geologist use an indirect method. When earthquakes occur, they produce seismic waves. Geologist record these seismic waves and study how they travel through earth. The speed of the seismic wave and the paths they take give geologist clues about the structure of the earth.


Pressure

Pressure-is the force applied perpendicular to the surface of an object per unit area over which that force is distributed.