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Volcanoes This power point has facts which are based on volcanoes.

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Presentation on theme: "Volcanoes This power point has facts which are based on volcanoes."— Presentation transcript:

1 volcanoes This power point has facts which are based on volcanoes.

2 How do volcanoes erupt? Volcanoes form when magma rises through cracks or weaknesses in the Earth's crust. Pressure builds and magma explodes to the surface causing a volcanic eruption. The lava from the eruption cools to form new crust. After several eruptions, the rock builds up to form a volcano.

3 How are volcanoes formed? Volcanoes are formed when magma from within the Earth's upper mantle works its way to the surface. At the surface, it erupts to form lava flows and ash deposits. Over time as the volcano continues to erupt, it will get bigger and bigger.

4 Here’s some pictures How the lava goes up. The start of an eruption. The big explosion.

5 here is a diagram of how lava goes up a volcano.

6 Volcano facts The word volcano originally comes from the name of the Roman god of fire, Vulcan. Volcanoes are usually located where tectonic plates meet. This is especially true for the Pacific Ring of Fire, an area around the Pacific Ocean where over 75% of the volcanoes on Earth are found. While most volcanoes form near tectonic boundaries, they can also form in areas that contain abnormally hot rock inside the Earth. Known as mantle plumes, these hotspots are found at a number of locations around the globe with the most notable being in Hawaii. Hot liquid rock under the Earth’s surface is known as magma, it is called lava after it comes out of a volcano.

7 We all say thanks for watching...


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