Thursday, October 28, 2010

What are volcanoes?
Volcanoes are kind of like mountains. They are created when magma inside of the earth escapes to the surface. Most volcanoes are found on the edge of the earth plates. There are 1500 volcanoes in the world.

How are volcanoes formed?
Volcanoes are formed when the magma hits the surface and it is called lava.
It is also formed when the lava flows down the volcano. (can also form when two plates split apart, leaving cracks in the earths crust)

How does an eruption occur?
An eruption occurs when two tectonic plates collide at a convergent boundary. Volcanic eruptions vary from gentle to violent depending on the amount of gas in the magma.
Different types of volcanoes.
Cinder Cone Volcanoes explode fiery clouds of ash rather than flowing lava. When they explode pieces of varying sizes called cinders fly high. The cinders that fly high are also the name of the volcano that is why they are call the cinder cone volcano.
Shield Volcano are large volcanoes that are built entirely out of fluid lava flows. It has shallow sides mounds. It got it name from the ancient warriors shield and it sits on the oceans crust.
Strato Volcano are volcanoes that has steep slopes and when it explode
it spits out clouds of ash and cinders. Some of the most famous volcanoes in the world are strato volcanoes. After the explotion, when the lava cools up it leaves layers and layers of lava and sometimes of layers of ash. This is the reason why they are also called composite volcano because of there slope sides.

The Largest Volcano
Mauna Loa is the biggest active volcano and also the largest volcano on
earth. It has erupted 33 times since 1848. Its last eruption was in 1984, it also erupted in 1942 during World War 2.

It is an extinct volcano.

I feel very happy that I live in Auckland because I can spot one extinct volcano right when I open my front door. (Mt Wellington)