1. earthquake Created by Team Four

2. What is an earthquake ？ The surface of the earth is made up of great tectonic plates of rock. These plates are all moving slowly towards, or away from, each other. Sometimes when they push together they slip and there is a jolt, and that is what we feel as an earthquake. The release of pressure caused by the grinding together of the tectonic plates creates the earthquake. Imagine the Earth's outer layer as being cracked into many pieces. These pieces, called tectonic plates "float" on the melted core of the earth. Because of this, they shift around ever so slightly and as they shift, they can grind against each other. This builds up pressure until the two plates slip, releasing their energy in what we feel as an earthquake.

3. What cause an earthquake ？ An earthquake is the violent shaking of the Earth caused by a sudden movement of rock beneath its surface. Rocks respond to stress (squeezed or pulled apart) near the Earth's surface by breaking, and when rocks move along either side of a fracture, it is called a fault. The land around a fault may shift horizontally, vertically, or a combination of these motions. The force that causes the stress within the rock is a result of movement of giant sections of the Earth's crust.

4. Plate movement Look at these two pictures, You can find the position of earthquake the convergent boundaries roughly overlap. This is a picture of the worldwide plate. This is the earthquake map in 1963-1998. Thus earthquakes are caused by plate extrusion.

5. Plate movement This is the type of plate movement.

6. The distribution of the earthquake  Seismic zone of the mid-ocean ridge: Contains stretches of the world's three oceans (Pacific, Atlantic and Indian Ocean) and the Arctic Sea mid-ocean ridge.Mid- ocean ridge seismic zone contains only about 5% of the world's earthquakes.  Eurasian seismic zone: On the boundary of the Eurasian plate and the African plate, the demise of the Indian plate.  Circum-Pacific seismic belt: The demise of the boundary of the Pacific plate and the American plate and the Eurasian plate, the demise of the Indian plate boundary, Antarctica plate and the Americas segment. Including the Pacific coast of the Americas, the Kuril Islands, the Japanese archipelago, Taiwan……. It is the most seismically active regions of the Earth, the concentration of more than 80% of the world's earthquakes.

7. Japan 311

8. You can see how terrible the tsunami triggered by the earthquake.

9. Japan earthquake magnitude Scale 9.1

10. The impact of earthquake on people Economic:The stock opened on crash. Because of Japan 311

11. The impact of earthquake on people Environment: The house collapsed ， the virus is everywhere proliferation.

12. Thank for listening!