The Earth is made up of 3 main layers: Crust, Mantle, Core
The layers of the Earth
Are different from one another
Crust
Thinnest layer of the Earth that ranges from only 2 miles in some areas of the ocean floor to 75 miles deep under mountains
Made up of large amounts of silicon and aluminum
Two types: oceaniccrust and continentalcrust
Composed of plates on which the continents and oceans rest
Mantle
Solid but capableofflow (like hot asphalt or fudge)
ThickestlayeroftheEarth (making up 70% of the Earth's mass)
The hot material (magma) in the mantle rises to the top of the mantle, cools, then sinks, reheats, and rises again. These convection currents cause changes in the Earth's surface
Upper Mantle
Extends from the crust to a depth of about 410 kilometers (255 miles)
Mostly solid, but its more malleable regions contribute to tectonic activity
Includes the lithosphere and asthenosphere
Lithosphere
The solid, outerpartoftheEarth, extending to a depth of about 100 kilometers (62 miles)
Includes both the crust and the brittle upper portion of the mantle
The coolest and most rigid of Earth's layers
Asthenosphere
The denser, weakerlayerbeneath the lithosphericmantle
Lies between about 100 kilometers (62 miles) and 410 kilometers (255 miles) beneath Earth's surface
The temperature and pressure are sohigh that rocks soften and partly melt, becoming semi-molten
TransitionZone
From about 410 kilometers (255 miles) to 660 kilometers (410 miles) beneath Earth's surface
Rocks undergo radical transformations, becoming much, much more dense
Outer Core
Molten (liquid) metal that is about 4,700°C (8,500°F)
Located about 1,800 miles beneath the crust and is about 1,400 miles thick
Composed of the melted metals nickel and iron
Inner Core
Solid sphere composed mostly of iron
As hot as 6,650°C (12,000°F)
Heat in the core is probably generated by the radioactive decay of uranium and other elements
Solid because of the pressure from the outer core, mantle, and crust compressing it tremendously
Temperature increases as depth increases
The lithosphere (crust and upper mantle) is divided into separate plates which move very slowly in response to the "convecting" part of the mantle
The two images show that the layers of the Earth include the crust, mantle, and core, and that the lithosphere is divided into plates that move slowly