[Q2] EarthSci - Layers of the Earth

• Earth's 3 Main Layers

  • Core (Inner and Outer)
  • Mantle
  • Crust
• Inner Core - center and the hottest layer of the Earth; solid, made up of iron and nickel with temperatures up to 5,500 °C
• Outer Core - 4000 to 9000 °F; all metals inside are liquid; around 1800 miles under the crust and is approximately 1400 miles thick; composed of motels such as iron and nickel; surrounds the inner core
• Mantle - widest section of the Earth, approximately 2900 km thick; mainly made up of semi-molten rock known as magma; rock is hard in the upper part, but lower down the rock is softer and begins to melt; located directly under the Sima; temperature varies between 1600 °F at the upper part to 4000 °F near the bottom
• Crust - outer layer where we live, thickness is around 0 to 60 km; most widely studied and understood; only about 3 to 5 miles (8 km) thick under the oceanic crust and about 25 miles (32 km) thick under the continental crust; temperature varies from air temperature on top to about 1600 °F (870 °C) in the deepest parts
• The crust is a solid rock layer divided into two types:

  • Continental Crust
  • Oceanic Crust
• Plates - float on the soft, plastic mantle which is located below the crust; usually move along smoothly but sometimes they stick and build up pressure, resulting into an earthquake
• The crust is composed of two basic rock types:

  • Granite - mostly on continental crust
  • Basalt - mostly on oceanic crust