The Earth’s Layers The earth is about 24,900 miles in circumference. 4 layers make up this portion of the earth. The Core---- This is the center of the earth and made up of solid iron or nickel *Inner Core - This portion of the core is solid *Outer Core - This portion is liquid Mantle----- This part has several layers. It contains most of the earth’s mass. The magma in the mantel is molten rock. Crust----- The thin layer of rock at the earth’s surface. It is 19 – 37 miles thick. Inside the Earth

Continental Drift Theory  This theory maintains the earth was once a super-continent that divided/slowly drifted apart over millions of years. The super-continent was known as PANGEA.

ON / ABOVE the EARTH Surrounding the earth is a thin layer of gas called the ATMOSPHERE The Atmosphere contains the oxygen that we breath, protects us from radiation , and space debris. The solid rock portion of the earth’s surface is known as the LITHOSPHERE This includes the upper mantle and the crust portion of the earth. Both the continents and the sea floor are part of the lithosphere. HYDROSPHERE is made up of all the water elements on the earth. It includes the oceans, seas, rivers, lakes, and water in the atmosphere. Together the atmosphere, the lithosphere, and the hydrosphere form the BIOSPHERE This is the pert of the earth where the plants and animals live.

Convergent Boundaries PLATE MOVEMENT Tectonic plates move in one of four ways: *spreading  or moving apart *subduction or diving under one another *collision  or crashing into one another *sliding past one another  in a shearing motion --Plates slide past one another Subduction Divergent Boundaries --Plates move apart, spreading horizontally --Plates collide, causing either one plate to dive under the other or the edges of both plates crumple Convergent Boundaries Transform Boundaries When tectonic plates come into contact, changes in the earth’s surface occur. Three types of boundaries mark plate movement.

Divergent Plates This happens when two plates are pulling away from each other. This gives room for magma (molted rock) to come up from the mantle. When the rock cools it forms land. MAGMA  LAVA http://earthguide.ucsd.edu/eoc/teachers/t_tectonics/p_seafloorspreading.html

Convergent This is when two continental plates collide. *Neither of them will sink. This type of plate movement has created some of the largest mountain ranges in the world. * ROCKY MOUNTAINS

Subduction * subduction, or diving under one another The ocean plate will slide under the continental plate http://SUBDUCTION

Faulting When plates slip along the sides of each other. This will create faults. San Andreas Fault

On the Pacific Plate : Most of the live volcano activity is around the world is located here. Ring of Fire Hot Spots: Holes in the middle of the tectonic plate that release the molten rock to create land.

PLATE MOVEMENT