6370 km 2900 km 2250 km Earth’s Interior Earth’s Main Chemical Composition 1220 km Earth’s Size Continental crust 10-75 km Ocean Crust 5-7 km Inner Core Outer Core Mantle (not to scale) Iron (Fe) Iron (Fe) Nickel (Ni) Sulfur (S) Iron (Fe) Magnesium (Mg) Aluminium (Al) Silicon (Si) Oxygen (O) Silicon (Si) Oxygen (O) Aluminum (Al) Iron (Fe) Calcium (Ca) Sodium (Na) A More Complicated Look Despite the popular Jules Verne novel, no one has journeyed to the center of Earth. As a result, we cannot say for sure how it looks, or exactly what it is composed of. It is important to remember that the straight lines in these more likely to look closer to the image on the right. Earth’s Movement Outer Core Mantle Island Arc Mid-ocean Ridge Volcanoes Subduction Subduction Hot Plume Trench Mohorovicic discontinuity: The boundary between the crust and the mantle Gutenberg discontinuity: The boundary between the mantle and core. education.nationalgeographic.com