Mount St. Helens: Remembering a natural disaster
30 years ago this week, the famous volcano erupted, changing the landscape forever.
Thursday, May 20, 2010 - 19:25
RECOVERY ON ITS WAY: More than 1,300 feet was blasted off the top of the mountain on May 18, 1980. (Photo: Austin Post, USGS)
I can't imagine what the world was like in 1980, a full 14 years before I was born! I read that people were busy watching a TV drama called "Dallas" because apparently the question, "Who Shot J.R.?" was on everyone's lips. I read that Blondie (who's Blondie?) had the number one music hit that year with "Call Me." Shoulder pads and big hair were in. (Who knew?) The one thing I do know that happened back then — 30 years ago this week — is that Mount St. Helens erupted. And while people have forgotten about J.R. and, thankfully, shoulder pads, people in the Northwest are still talking about the giant eruption.
The Burke Museum of Natural History and Culture in Seattle is calling the eruption the biggest natural event in the Pacific Northwest of our lifetime. (Well, maybe of your lifetime.)
It all started with a series of small earthquakes that shook the area where the most active volcano in the Cascade Mountain Range is located in southern Washington. It's estimated that 10,000 earthquakes rocked the mountain between March and May of 1980 when Mount St. Helens finally erupted. The mounting lava from the mini-events created a dome that grew to 450 feet. On May 18, within minutes of a jolt from a large earthquake measuring 5.1 on the Richter scale, the volcano's bulge and summit slid away in a landslide the U.S. Geological Survey calls "the largest on Earth during recorded history."
The landslide "depressurized" the system of magma that had built up in the volcano, causing the blast to move up and out in a lateral motion, leveling forests. A vertical eruption or "eruption column" blasted 15 miles high into the atmosphere in just 15 minutes. A second eruption column formed as magma was forced from the new crater. The volcanic eruption peaked during the next eight or so hours. During that day, it is estimated that 520 million tons of ash were blown by the prevailing winds, causing complete darkness in Spokane, Wash., some 250 miles away. It took three days for the ash to reach across the United States and 15 days to travel around the globe.
The landscape (including wildlife habitat) has been changed forever. But 30 years later, Mother Nature's nurturing side is apparent. Resilient species such as red alder trees have rebounded and now a deciduous woodland has developed — attracting birds, like neotropical migrants with populations are in decline. More than 130 new ponds supporting a host of frogs, toads and salamanders have been formed. Even rodent populations that survived the volcano under the Earth's surface in their burrows have added soil to the top of the ash by bringing it up from below. The area covered by flows now serves as a giant laboratory for scientists who are monitoring ecosystem recovery.
The mountain is a national treasure: a dynamic landscape that reminds us how beautiful, strong and alive our planet is.
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