Structure of the Earth

What are the layers of the Earth  Crust  Thin layer of rock  Surrounds Earth like a shell surrounds an egg  Two types of crust Continental crust Makes up the continents and some major islands Oceanic crust Makes up the ocean floor  Between 6-70 km thick (about 3.7 – 43.5 miles)  Furthest we have ever been in 12.3 Km (7.6 miles) – This is 0.2% of the way there

Two Kinds of Crust  Continental Crust  Thicker of the two  Less Dense  Composed mostly of Granite  Avg. of 20 – 40 Km thick (12 – 24.9 Miles)  Oceanic Crust  Thinner of the two  More Dense  Composed mostly of Basalt  Avg. of 6 – 11 Km thick (3.7 – 6.8 Miles)

Mantle  Thickest Layer of Earth  Made mostly of Hot Molten Rock  Very, Very top is cool ridged rock  About 2900 Km (1802 miles)  870 – 4400 C (1598 – 7952 F)

Outer Core  Layer of liquid metal  Iron & Nickel  2300 Km (1429 Miles)  4400 – 6100 C (7952 – 11,012 F)  There is more pressure than the mantle but less pressure than the inner core

Inner Core  Solid ball of metal  Iron & Nickel  2400 Km in diameter (1491 Miles)  7000 – 8000 C (12,632 – 14,432 F)  Extreme pressure keeps it solid  Densest layer of the Earth

Lithosphere  Made up of the crust and very top rigid part of the mantle  This is what the tectonic plates are made of  Most plates have both continental and oceanic crust  On continents it is believed to be an average of 150 Km (93 miles)  In ocean it is believe Km (31 – 62 miles)

Asthenosphere  The hot soft layer of molten rock in the middle mantle on which the lithosphere rests  Flows slowly like hot tar  Estimated to be 85- several hundred Km thick (50 – several hundred miles)