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Mount St. Helens – Leading up to a Natural Disaster

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Introduction

h/w 22 September 2002 Mount St. Helens - Leading up to a Natural Disaster One of the world's biggest volcanoes, Mount St. Helens, had the world watching in awe as the lava underneath broke free and caused 57 innocent deaths and destroyed miles of land and life form around it in 1980. The volcano is situated in the southwestern portion of the state of Washington, in the United States. Being in the USA, it had a slight advantage as it was the most developed country and had the equipment and knowledge to monitor the volcano for future use. It all began in 1969, when a geologist of the US Geologist Survey (USGS), described the volcano as 'a young, active and dangerous volcano.' 3 years later seismometers and geodimeters were installed by the USGS, so they could monitor the mountain. 8 years went on before the USGS announced the volcano could erupt in the next hundred years instead of the next thousand years as previously predicted and could be as early as before the century end, about twenty two years away. ...read more.

Middle

On the 3rd of April, harmonic tremors were recorded which tell geologists that there were movements of magma underneath the volcano. A lava dome also started to swell on the north flank of the mountain growing by about a meter a day. This was due to the diverted magma. In 9 days time it had grown be 2 km in diameter, and stuck out by over 100m. This was directly above the Earthquake swarm focus and the source of the harmonic tremors, and acted as a lid for the lava pressure. By the end of April 1980, all the summit craters become one big one, measuring 500m wide and 200m in depth. This lead to a 30 km radius 'danger zone' was erected, angering thousands of sightseers from across the world. On the 7th of May the steam and ash eruptions began once again. Two days later, USGS scientists said that the town of Toutle, 25 km away from the volcano, "Instead of a huge slide where the whole north side of the mountain would come down at once ... ...read more.

Conclusion

In about 4 minutes of the blast around 360 km2 had been devastated. The mudflows grew to be 50m deep and 1 km wide in some places. Everything in its path was destroyed indefinitely and before clogging up valleys with its mud, rock debris, and shattered timber. Deposits by the mudflows were at one point about 200m thick in the northern valleys of the river Toutle. The ash left by the volcano reached heights of 20000m and covered parts of northwestern USA. Once the air had started to clear up a bit a few days later, it was then clear to see what had really happened. The blast had blown of the top of the mountain reducing the height of it by nearly 500m. A week later ash eruptions still continued to occur. The blast had also destroyed all life in an area of some 180 km2. The destruction of the earthquake was massive but could not really have been prevented as we cannot do anything to stop nature take its cause. Warnings could have prevented 57 people dieing but who was to now when it was going to happen. ...read more.

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