Mount St Helens
on March 27, 1980, U.S. Geological Survey issued an official Hazard Watch for Mount St. Helens. On March 27, a crater had formed through its summit ice cap and had grown 1,300 feet in diameter. Four days later, instruments set up by volcanologists that used lasers placed in a mountain ridge six miles away to record change picked up volcanic tremors, which meant that magma was on the move. In April, laser equipment detected changes in the mountain’s profile- an ominous swelling bulge forming between the fissures (Mary Bagely). Laser measurements showed a bulge was that growing at about five feet per day by late April. By May 17, a total of 10,000 earthquakes shook the volcano and the north flank had grown outward at least 450 feet to form a bulge (magma had risen high in the …show more content…
Along with that, a plume of the volcano was blown 80,000 feet in air and rained down 250 miles away in Spokane. The winds blew 520 million tons of ash eastward 2,200 miles across the U.S. in seven states and caused complete darkness in Spokane, Washington, which was 250 miles from the volcano. The blast also wiped out 230 square miles of forestland. With the accumulation of airborne debris, the ash cloud encircled the globe in 15 days. In the end, along with the total land area destroyed, a total of 57 human lives were lost, along with about 7,000 big game animals and 12 million salmon fingerlings in hatcheries (Mount St. Helens – From the 1980 Eruption to 2000).
The eruption of Mount St. Helens on May 18, 1980 was the worst recorded eruption and landslide in U.S. history. Multiple minor quakes and eruptions had lead up to the major eruption that will forever remain in the minds of those who experienced it. The mountain had been downsized and lots of land was destroyed, along with people’s comfortability with the mountain. The world will never look at Mt. Saint Helens the same way ever