The Eruption of Mount Saint Helens

Made by Electra NicolaysenFernando III El Santo

Monday, 16 December 2013

Mount Saint Helens is a volcano in Washington state, in the United States.

Although Mt. St. Helens was moderately active several times in the 19th century, no one expected the volcano to erupt as it did.

In 1980, park rangers and scientists were concerned because the side of the volcano was

growing larger…

People who lived near Mt. St. Helens were worried that they would lose their homes.

The bump on the side of the volcano grew larger and larger for several

months…

Mt. St. Helens was monitored by the University of Washington beginning in March of 1980, and several earthquakes of 4+ magnitude were recorded. The early detection of volcanic activity saved many lives.

The U.S. Geological Survey issued a Hazard Watch for Mt. St. Helens on March 27, 1980. The same day, the

first eruption of steam sent a steam column 1,829 meters into the air.

Volcanologists monitored Mt. St. Helens and found “volcanic tremor,” pulses that indicated magma within the volcano was on the move. The bulge was growing at a rate of almost 2 meters a day.

On May 18, 1980…

• A volcanologist named David Johnston sent a report of the data he was gathering about Mt. St. Helens. The report showed no unusual activity.

• Suddenly, there was an earthquake one mile beneath the volcano.

• The earthquake caused the bump on the volcano to collapse…

• Then, there was an avalanche. The release of pressure caused the volcano to erupt.

Mt. St. Helens erupted.

The Eruption of Mt. St. Helens

• MSH Eruption Footage• The Blast• Example of a Lahar

The avalanche and eruption killed 57 people.

The surrounding area was damaged by the avalanche, debris, and ash.

Many trees were killed and the terrain was damaged by floods and burnt.

Ash from the eruption spread all over the northwestern United States. The ash erupted for over nine hours and sent 540 million

tons of ash over seven states.

The heat from the eruption vaporized ice and snow around the volcano and caused lahars (mud flows)

which moved at 145 kph and wiped out everything in their paths.

Destruction Caused by Mt. St. Helens

• 57 people were killed• 200+ homes were destroyed• 185 miles of roads and 15

miles of railways were damaged

• Ash clogged sewer systems and temporarily stopped air traffic in the Northwest

• $950 million was spent on recovery efforts

• An estimated $1.1 billion of lost revenue for the timber industry.

This is Mt. St. Helens today. The volcano is constantly monitored as scientists fear it will erupt again.