Download volcanoes

volcanoes
This power point has facts which are based on
volcanoes.
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.
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.
Here’s some pictures
How the
lava goes
up.
The start
of an
eruption.
The big
explosion.
here is a diagram of how lava goes
up a volcano.
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.
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