What is a Volcano?

For the catastrophic event I chose the volcanic eruption, because the eruption of the Mt. Saint Helens was always in my curiousity. Volcanic eruptions usually occur when the hot magma that’s been rising steadily finally pushes it’s way out of the earth’s crust. The occurrence of the eruption is totally dependent on the volcano itself. For example Mt. Kilauea almost never stopped erupting while Mt. Pinatubo hasn’t erupted since 1991. When the eruption occurs, the area affected by the volcano is very dependent on the magnitude of the volcanic eruption. For example if the volcanic eruption is very weak, it will only affect up to the county level; however, if the volcanic eruption is categorized as huge, it can affect the whole coastal zone. People are usually aware of the eruption months before it happens by the geological changes. For example Mt. Saint Helens started moving towards Seattle each month until it erupted.

Mt. Saint Helen 1980

On May 18, 1980, Mt. Saint Helens located in Skamania County finally erupted after months and months of small eruptions and warnings which indicated that the huge eruption was inevitable sooner or later. A magnitude of 5.1 earthquake rang the bell that indicated the start of the cataclysm. Shortly after the earthquake, disastrous volcanic eruption of Mt. Saint Helens occurred which was so devastating that the debris rose up 600 feet and stretched 14 miles out of the site of the volcanic eruption. On top of everything this humongous volcanic eruption caused a huge landslide known as lahars that swept over most of the area around the site. This volcanic eruption left 57 fatalities and 200 square miles of forest and 30 miles of State Route 504 burnt down. Even though this volcanic eruption was recorded to be one of the biggest explosion in the history of U.S but the fatalities weren’t as big as it would have been expected. This was because of the early cautions and warnings that the Mt. Saint Helens let out, such as: small volcanic eruption that indicated that a big one was yet to come; Mt. Saint Helens moving closer and closer to Seattle each month. Also the officials had most of the residence around the Mt. Saint Helens retrieve their belongings and evacuate the area on May 17, a day before the eruption. This kind of eruption is likely to occur in the same place, because there aren’t any other volcanically active, or has been active, mountains other than Mt. Saint Helens.

COSPEC - Sulfur Dioxide Correlation Spectrometer

This technology is used to examine how much Sulfur Dioxide is present around the volcanoes. These technology is used by vulcanologist, people who study volcanoes, and it usually predicts when the volcano will erupt. It was developed in the 1960's in Canada to examine, or predict, the occurrence of the volcanic eruption. COSPEC shows the amount of SO2, otherwise sulfur dioxide, by the change in colors. More SO2 present around the volcanoes, stronger the color intensity shown in the graphs produced by these technologies. 

Bibliography

Lange, Greg. "Mount St. Helens Erupts on May 18, 1980." Historylink.org. History Link, 15 May 2003. Web. 25 Jan. 2013.
Wiltgen, Nick. "Worst Western U.S. Disasters." The Weather Channel. Weather Channel, 12 Oct. 2012. Web. 28 Jan. 2013.

 Perkins, Sid. "A Fresh Look at Mount St. Helens." Science News. 24 Apr. 2010: 18. eLibrary. Web. 28 Jan. 2013.
"Saint Helens, Mount." Compton's by Britannica, v 6.0. 2009. eLibrary. Web. 28 Jan. 2013.