The Core By Kevin Fuquay And Hunter Smith Period 5 The Core • Discovered by Seismologist Inge Lehmann when certain earthquake waves passed through and others didn’t. • Divided into 2 parts: Inner Core and Outer Core. • The source of the Earth’s magnetic field. • Rotates faster then the Earth. • 15% of the volume of Earth. Inner Core • 3160-3954 miles deep. • Radius is 758 miles (70% the size of the moon.) • Believed to be made of iron-nickel alloy. • Temperature is believed to be 9800 degrees Fahrenheit. • Slowly cooling: about 100 degrees Celsius every billion years. Outer Core • About 1790-3160 miles deep. • Liquid Core made of iron and nickel. • Currents in the outer core believed to cause the magnetic field. • Not under enough pressure to be solid. • Temperature believed to be 7200-9032 degrees Fahrenheit. Magnetic Field • Caused by the presence of the core. • Protects Earth from solar winds, creates protective shield around Earth. • Without the magnetic field, Earth would be like Mars (the solar wind would destroy the atmosphere) . • An example of a magnetic dipole (closed circulation of electric current.) • North and South poles. Earths Other Layers • Crust is the outermost layer, thin (about 1% of Earth’s volume) , made of sedimentary, igneous and metamorphic rock. • Plate Tectonics sit on the crust. • Mantle is largest part of earth (84%). • Solid, made of rocks like peridotite, dunite and eclogite . • Temperature is 932-1652 degrees Fahrenheit.