2Earth’s LayersSometimes Earth is described as a giant rock in space. In one way, that’s true. Earth’s surface is solid and is made of rock and soil. But Earth has different layer, and are all made up of different materials.
4CoreAt the very center of the Earth is the core. It is made mostly of Iron Temperatures at the Core are thought to be as hot as 7,000 degrees Celsius (that’s as hot as the surface of the sun).
5The Inner CoreThe inner core is a solid made up of mostly iron. It is about 1,255 km radius.1255 km
6Outer CoreThe outer core is liquid. The liquid in the outer core flows in currents. These currents make Earth’s magnetic field. Scientists believe that the outer core is made of iron mixed with smaller amounts of other materials.2221 kmOuter CoreInner core
7Questions about the Core: Where is the Core located?Is the inner core a solid or a liquid?Is the outer core a solid or a liquid?What is the Core mostly made of?What is the temperature of the core thought to be?
9MantleThe mantle is the layer that makes up most of Earths material. This layer is made mostly of oxygen combined with silicon, magnesium, and iron. The top part of the mantle is solid hot rock. Deeper in the Earth the mantle is under very high pressure. Its temperature ranges from about 360 degrees Celsius to 2500 degrees Celsius. Convection currents flow slowly in the mantle. In these currents, cooler rock flows down and hotter rock flows up. High temperatures inside Earth provide the energy needed for those currents to move. The lithosphere floats on the top of convection currents in the mantle.
13CrustWhen you stand on the ground, you are on the crust, Earth’s outermost and thinnest layer. It includes the soil and rock that covers Earth surface. The thickness of the crust varies. Part of the crust covered by ocean water is about 6-11 kilometers thick, the part that is dry land is about kilometers thick. When you think about high mountains, which are part of Earth’s crust you might think the crust is thick. But compared to the size of Earth, the crust is just a thin shell.
14Two Kinds of Crust There are two general kinds of crust. Continental crust makes up the lands of thecontinents. It can be about 75 kilometers thickand is mostly granite.Oceanic crust lies beneath most of the ocean floor, and is made of different kinds of rock than the continental crust. Oceanic crust is made mostly of basalt, which is a dark green or black rock. This crust is about 6 to 11 kilometers thick.
15Questions about the crust Where is the crust located?What are the two types of crusts?