What are Volcanoes and Earthquakes?
What is a Volcano?
A volcano is a mountain with an opening that reaches down into the earth. Sometimes, when pressure inside the earth builds up, a volcano can erupt. An eruption occurs when lava shoots out and spills down a volcano. Lava contains ash, cinders, and hot, molten rock. When the hot lava cools, it gets hard and makes new rock. A volcanic eruption can cause damage and changes to the landscape.
How Do Volcanoes Form?
The earth is made up of three layers. The most inner layer is the core, the middle layer is the mantle, and the outer layer is the crust. Volcanoes begin in the mantle, where hot, pasty rock called magma forms. Sometimes, magma gushes out of weak spots in the crust, but magma usually rises and comes out of the top opening of the volcano. Each time a volcano erupts, the volcano grows bigger.
Are there any volcanoes in the U.S.?
One of the volcanoes in the U.S. is Mt. Saint Helens. Mt. Saint Helens in a volcano located in the state of Washington in the United States. This volcano last erupted in 1980. The eruption lasted almost nine hours. Volcanic ash from the eruption spread all throughout the state- some ash even made to its way to the neighboring state of Idaho!
What about Earthquakes?
Similar to volcanos, earthquakes also begin inside the earth. An earthquake is the sudden shaking or rolling of the earth. Beneath the earth's surface are plates. When these plates shift, the earth might shake, resulting in an earthquake. Some earthquakes are small and can barely be felt by humans. Others are larger and can cause damage to the surrounding areas.