3. Layers of the Earth The core – composed of iron and nickel. Extreme pressure. Density is 13 times heavier than water. Inner core is solid; outer core is liquid. The mantle – contain over 82% of Earth’s volume. Heat from core gets transmitted through mantle to surface. Average density is 3.5 times heavier than water.

5. The Earth’s layers Lithosphere – Earth’s outermost layer consists of the crust and upper mantle. It is a relatively cool and rigid shell. Asthenosphere – below lithosphere; the upper part of the mantle. Rocks are close to their melting temperatures so they easily deform.

8. Transfer of Energy Convection currents – heat generated in the Earth’s interior comes up to the surface where it cools and moves back down. This energy is what moves the Earth’s plates and causes earthquakes and volcanic eruptions in some places. http://www.youtube.com/watch?v=Q9j1xGaxYzY

10. The Earth’s plates The Earth’s rigid lithosphere is divided into over 25 separate plates that are very big to very small pieces of the crust. There are seven large plates that make up the Earth’s crust. Each plate “interacts” with the plate that is next to it. These places are called plate boundaries.

12. Different types of crust The Earth’s crust has two types: Ocean crust is thinner (3-5 miles) and denser. The main type of rock is basalt. Continental crust is thicker (5-25 miles) and less dense. The main type of rock is granite.

13. <<< GRANITE BASALT >>>

15. The Ring of Fire The land that borders the Pacific Ocean has numerous earthquakes and volcanoes caused by the movement of the crust. New Zealand, Philippines, Japan, Aleutian Islands (Alaska), Cascade Mountains (US) Andes Mountains (South America)

16. Andes Mountains are volcanic. To the West of this mountain range is a deep Trench called the Peru-Chilean Trench

18. The Cascade Mountains of the Pacific northwest are also volcanic like the Andes Mountains. The Juan De Fuca plate (ocean crust) Is more dense and goes beneath the North American plate (continental crust) creating A volcanic mountain range

22. Island Arcs When two ocean plates meet, both are the same density, but one goes below the other. This creates volcanic islands in the ocean called island arcs.

28. India collides with Asia In the past 65 million years, the plate that holds India has broken away from Africa and moved north colliding with Asia. This collision has formed the Himalayan Mountains of India, Nepal and Tibet.

34. Diverging plate boundaries Plates coming apart or rifting. This is happening today at mid-ocean ridges, which are underwater mountain ranges throughout the world. It is also happening in the Red Sea, the Sea of Cortez and the Great Rift Valley of Africa.

37. How it happens?? Magma comes to the surface and splits the plate apart. The two separate plates move in opposite directions. New crust is always being created where plates diverge (move apart) The heat that causes this to happen comes up from the core through the mantle to the crust in various places.

39. Iceland Iceland lies atop the mid-Atlantic ridge. It is an island country with lots of snow and ice as well as hot springs, geysers and volcanoes.

42. The Azores The Azores, off the coast of Spain, are islands that used to be on the mid-Atlantic ridge but got moved as the plates continued to separate.