Earth Structures Day 1

The innermost layers are mostly different kinds of metal Earths layers The earth is made up of many layers and many of these layers are composed of solid or partly melted rock. The innermost layers are mostly different kinds of metal

Crust Like the crust on a piece of bread the crust is the outermost layer of the Earth. The crust is much thinner than the other layers of the Earth. The crust is nearly all solid rock The average thickness of the crust is about 24mi or 40km in some mountainous regions it can reach 42 mi or 70km thick. (continents) The average thickness of the crust under the ocean is even thinner! It is about 4 mi or 7km thick!

Interesting Fact: The temperatures increase the deeper you go into the Earth…. So the deeper you go into the Earth the hotter the rocks are. You might be asking: How do scientists know how hot the rocks are at the center of the Earth? Scientists studied mines and holes drilled into the crust and they learned that the temperatures increase about 2-3 degrees Celsius for about every 300ft or .1km.

Mantle The layer just below the crust The mantle is about 1,800 mi or 2,900 km thick and makes up more than two- thirds of Earth’s mass. Upper mantle (the part that touches the Crust) is made of solid rock ** the solid upper mantle and the crust combine to make the lithosphere. **** Wait what is the Lithosphere? The lithosphere is the land that we live on. The continents were formed by the lithosphere . There is also the hydrosphere which is the oceans and other bodies of water. This is also created by the upper mantle.

Mantle Below the lithosphere much of the rock material in the mantle is partially melted. The material flows slowly like melted plastic The solid lithosphere is thought of as floating on the liquid lower mantle.

Core The innermost of Earth’s layers is the core. The core extends to the center of the Earth. There are two regions of the core, the outer and the inner core.

Outer Core The outer core is 2,200km or 1,400 mi thick and it is the only layer that is considered to by in a liquid state. It is made up of molten iron and nickel with some sulfur and oxygen also present

Inner Core The inner core is about 1,200 km or 720 mi thick. It is even hotter than the outer core It is believed to be made up of iron and nickel The high pressures that are created that deep into the Earth keep the inside of the Earth from melting.

Fact to think about: Many scientist think that the presence of molten iron and nickel in the Earth’s core explains why Earth is surrounded by a magnetic field.