Washington – Exactly 36 years ago, Mount St. Helens erupted 60,000 feet into the air, marking the deadliest volcanic eruption in the history of the United States. It left 57 people dead, destroyed more than 200 homes and 27 bridges. Nearly 7,000 big game animals along with 12 million juvenile salmon were lost as a 5.2 magnitude earthquake triggered the biggest eruption to hit the volcano in 123 years.
The astonishing phenomenon occurred at 8:32 a.m. on May 18, 1980, causing the most economically destructive eruption in the country, according to the U.S. Geological Survey (USGS). The eruptional blast destroyed an area more than 12 miles north and nearly 19 miles from west to east.
The earthquake, which led to the nine-hour cataclysm, triggered the largest debris avalanche as it wiped out the northern summit of Mount St. Helens and exposed its core, as reported by CBS News.
KOIN-TV correspondent Ken Woo reported for CBS News that the explosions could be heard nearly 200 miles away. It was a dark morning across the state, as winds drifted 520 million tons of ash across Washington and even people in Spokane, located 250 miles to the northeast, found themselves under rarely dark skies.
Volcanic activity after the massive eruption in May 1980
The Mount St. Helens has experienced several small blasts since the one in May 1980. The most significant occurred in spring, summer and fall that year. In fact, the volcano’s northern flank rose 5 feet due to the magma that pushed the ground higher.
Volcanic activity in 1980 and in the 2000s have caused tall domes to form and restore 7 percent of the lost volume. The USGS says the volcano will probably erupt again soon, but the fact that a deep crater has appeared at the top of Mount St. Helens makes it unlikely that the state will see a massive eruption in the near future.
Mount St. Helens’ latest activities
About 130 tremors occurred on the volcano earlier this year. People felt the swarm of earthquakes between March 14 and May 9, but USGS experts and scientists from the Pacific Northwest Seismic Network affirmed those 1.3 magnitude events were not a cause of concern.
The USGS explained that the events were just a sign that the system was slowly recharging.
“The magma chamber is likely imparting its own stresses on the crust around and above it, as the system slowly recharges. The stress drives fluids through cracks, producing the small quakes,” the USGS reported earlier this year.
After all, there is always some kind of activity in a volcano, as Joan Gomberg, a geophysicist with the USGS’ office based in Seattle, told Oregon Live on Monday. He commented that there is something going on in all the Cascade volcanoes.
The 1980 ground collapse has helped scientists identify other magmatic events
36 years later, scientists use the massive eruption as a reference to easily detect other past and present magmatic phenomenon. Since 1980, experts can identify the signs of “sector-collapse eruptions”, according to Michael Dungan, volcanologist and courtesy professor at the Department of Geological Sciences at the University of Oregon, as reported by Oregon Live.
“To a large degree, Mount St. Helens was a turning point for active volcano monitoring and volcano science,” said Dungan.
He has been involved in global research and works since he graduated from the University of Washington in 1974. Dungan said he has been able to identify a number of similar eruptions in Chile and other South American countries.
Source: Oregon Live