Mt St Helens, a volcano in Washington State, had a huge eruption on May 18, 1980. The damages were over a billion dollars, and 57 individuals lost their lives. Far from the worst volcanic eruption on record, but one of the most shocking. Ever given that then, Mt St Helens has been viewed like a hawk, and more than a few short term loans went into repairing the damage.
Mt St Helens 1980 eruption
Mt St Helens had been dormant for more than a century, but in March 1980, earthquakes started to shake the mountain. Once the earthquakes , the volcano was closely monitored. On May 18, an earthquake with a magnitude of 5 on the Richter scale shook the mountain. It triggered a landslide on the North face, which provided an outlet for the intense heat and pressure inside the volcano. Gas, magma, rock and other debris blasted out of the side.
The explosion blasts
A pyroclastic blast traveling at the speed of sound exploded out of the side as a result of the landslide. The debris was shot 20 miles away. 17 different pyroclastic flows leaked out of the side following the original explosion. The pyroclastic flows were still over 800 degrees Fahrenheit in temperature two weeks later.
Damages
A 20 mile swath of destruction flowed straight out of the volcano. Mud flow and debris flows clogged river systems, causing floods and causing extensive damage to river systems. The volcano spewed forth over a cubic mile of debris. 200 homes, 27 bridges, 15 miles of railway and 185 miles of highway were destroyed, and 57 perished. President Carter declared the landscape as desolate as the lunar surface.
Ripple effects
An ash cloud extended 12 miles into the atmosphere. Washington State was covered with ash, with the city of Yakima getting a heavy coat by the next day. The city of Spokane, almost 300 miles away, was plunged into a primordial darkness with 10 feet of visibility. Ash was reported as far away as New Mexico and Minnesota. Just as the recent Iceland volcano eruptions have, airports canceled flights for days on end. The energy released by the blast was 1,600 times more powerful than the nuclear bomb that was dropped on Hiroshima. The mountain was left over 1,000 feet shorter and with a crater almost 2.5 miles wide. Smaller eruptions and occasional activity still occur. Over $ 1 billion in damage was done by the Mt St Helens eruption. For all her beauty and bounty, Mother Nature is indeed the harshest of mistresses at times.
Citations
Mt St Helens
http://en.wikipedia.org/wiki/1980_eruption_of_Mount_St._Helens
