VolcanoesBy Camilla and

Megan

Volcanoes

• Volcanoes are formed when there is a weak spot in the crust, and magma comes to the surface. It is formed at weak spots, diverging boundaries and Convergent Boundaries. They have 3 main parts, The Magma Chamber, the Pipe and The Vent. They erupt because of the pressured gas in the lava. They have quiet and explosive eruptions. There are many different types of Volcanoes.

Shield Volcanoes Shield Volcanoes are made of thin layers

of lava. The lava builds up a wide mountain-like Shield Volcano. A well known Shield Volcano is the hot spot on the Hawaiian Island’s Ocean Floor. Myth is that a soldier died with his shield laying next to him.

Cinder Cone Volcanoes

A cinder cone volcano has high viscosity. Sometimes it will make bombs, cinders or even ash. This material is in a steep hill that is shaped like a cone. One example of a Cinder Cone is Paricutin in Mexico. It created a cinder cone that was 400 ft, high

Composite Volcanoes If lava flows near explosive

eruptions, you will find a composite volcano. Composite volcanoes are like Cinder cones. They are shaped like a cone and pretty tall. An example is Mount St. Helens in the U.S. Another example is Mount Fuji in Japan.

Lava Plateau Many volcano eruptions form

mountains. But, some form high land called a lava plateau. Small amounts of lava flow through big cracks, then dry off and turn hard. This happens again and again, over and over. After a long period of time it forms a plateau. An example is Columbia Plateau. It covers area of Oregon, Idaho and Washington.

Caldera

• A Caldera is formed when a explosive eruption causes a volcano to blow it’s top off. Some part of the Volcano and ash remain. It is filled with water, turning it into a lake. Crater Lake is a Caldera

Volcanic Necks

• Volcanic Necks are made from Lava. When it has dried in the pipe, and the rest of the volcano has worn away. Ship Rock in New Mexico is a Volcanic Neck

Dikes and Sills

• Dikes and Sills are Volcanic Landforms.