Essay on Earth Science

5912 Words Nov 2nd, 2015 24 Pages
Earth Science: Volcanoes
Report by: Kenneth Ragragio

What is Volcanoes? * Volcanoes are vents that allow lava, rock fragments and gases to escape from layers beneath the earth's surface. Learn how volcanoes form both on land and underwater and why they erupt. * Volcanoes are spectacular events and because of this, they have found their way into the plot of many Hollywood movies. While the movies have given most of us the vivid image of red-hot lava spewing out of the top of a towering volcano, they do not share the entire story of volcanoes
Magma and Lava * So what exactly is a volcano? Well, it can be defined as a vent in the earth's crust through which lava, rock fragments, hot vapor and gases are ejected. In other
…show more content…
However, it has done so in recordable history. A dormant volcano is also expected to have an eruption sometime in the future. Sometimes the difference between a dormant volcano and an active volcano can be pretty small. That is because even though a volcano can be dormant for hundreds of years it is still expected to have an eruption in the future. Mauna Kea is a volcano which is located on Big Island and its last eruption took place 3,500-4,000 years ago. However scientists believe that it will erupt again. What makes that volcano dormant is that currently there is no prediction as to when that eruption could take place. A dormant volcano could be very dangerous because people in the surrounding areas are usually not prepared and complacent leaving close to the mountain. Before its eruption in 1980, Mount St. Helens was dormant. 3. Extinct Volcanoes
An extinct volcano is a volcano that no one expects will ever have another eruption. One such volcano is also located on Hawaii’s Big Island and its name is Kohala. The last time that Kohala erupted was close to 60,000 years ago. As of now scientists do not believe that volcano will ever be active again. Keep in mind that this classification of volcanoes that are extinct is not necessarily definitive as some have gone through what is called rejuvenation.

Type Classifications *

Related Documents