Ch. 7.1: Inside the Earth

Earth’s layers The Earth is divided into three layers 1.) Crust 2.) Mantle 3.) Core Crust and Mantle are made of less dense compounds Oxygen and Silicon Densest compounds make up the core Iron and Nickel

CH 7.1 Crust -Thinnest layer of the Earth 2 types: 1.) Continental Crust – Oxygen, Silicon and Aluminum - Granitic Rock 2.) Oceanic Crust– More dense because it contains Iron, Calcium and Magnesium. - Basaltic Rock

Mantle – Layer between the crust and core -contains most of the earths mass (67%) -Magma that flows to the surface gives us clues about the composition of the mantle -Is more dense than the crust because it contains more Magnesium and less aluminum and silicon Core is the central part of the earth -makes up 33% of the earths mass -most dense layer -made up of mostly Iron, some nickel, and almost no Oxygen and Silicon

Lithosphere – outermost crust -divided into tectonic plates Asthenosphere- plastic layer Which lithosphere moves on top of Mesophere-Strong lower part of the mantle Outer Core – liquid layer of the core Inner Core – Solid dense center

Tectonic plates are pieces of the lithospere that move around on top of the asthenosphere

By measuring the changes in speed of seismic waves, scientists have discovered that the earth is made of different layers Pg. 196 Figure 6

10.2: Restless Continents