Our Dynamic Earth By StarShineSandy, tbanana123 and Spencerdog!

Introduction We would like to share our knowledge about our Dynamic Earth. In this Power point there is lots of different information. We hope you will learn lots of new information about our Dynamic Earth. We hope you enjoy!

Contents 1.What are Plate Tectonics? 2.Structure of the Earth 3.Earthquakes explained 4.Tsunamis explained 5.Volcanoes explained 6.Pacific Ring Of Fire 7.Diagrams 8.Glossary 9.Pictures 10.Thanks

What are Plate Tectonics? The Earth is moving beneath our feet. Its hard shell, lithosphere, is made up of continental crust and mantle. It is divided into 17 plates, which drift on the upper mantle. Plates beneath the oceans are thin but made up of heavy material, but continental plates are made of light, thicker material. Some plates move apart (divergent), overlap (convergent) and rub against each other (transform). These all lead up to mountains, volcanoes, ocean trenches and earthquakes.

The Structure of the Earth The earth is made up of 3 main layers: Core Mantle Crust The crust is what we live on. There are 2 types of crust: Continental crust Oceanic crust

Earthquakes Explained Earthquakes occur on plate boundaries where there are faults. Friction causes stress to the plates and then when the stress becomes to much and that causes an earthquake. There are three main faults: strike-slip, normal and reverse or thrust faults.

Tsunami’s Explained A tsunami occurs when plates rub together creating an underwater earthquakes. This creates massive waves that hurl themselves towards the shore. When there is a lot of wind it can make a larger wave. Tsunamis can travel at speeds of up to 590 mph.

Volcanoes Explained About four-fifths of the Earths surface is volcanic rock. Some volcanic eruptions are violent explosions of lava, gas and ash. Where two oceanic plates move apart, gentle eruptions produce long volcanic ridges on the seafloor.

Pacific Ring of Fire An area where a number of earthquakes and volcanic eruptions occur in the basin of the Pacific ocean. Roughly 90% of earthquakes occur along the Ring of Fire and dotted with 75% of volcanoes on Earth. There are 452 active volcanoes along the Ring of Fire. The Ring is shaped like a horse-shoe.

Diagrams

Glossary Lithosphere – the outer part of the Earth. Oceanic Crust – the part of the earth we live on but underwater. Continental Crust – the part we live on (not underwater) Mantle – the layer of the Earth underneath the crust.

Pictures The blue Lagoon in Iceland is heated by a volcano

Thanks For Watching