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Science
Friday > Archives
> 2000
> May
> May 19, 2000:
Hour Two: Mt. St. Helens
20th Anniversary
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Two photos of Mt. St.
Helens, from the same viewpoint.
The image on the left was taken May 17, 1980, the day before the
eruption. The image on the right was taken September 10, 1980.
Both images by Harry Glicken, USGS |
May 18, 1980, 8:32 am. Pressure had been building beneath Mt.
St. Helens, a peak in the Pacific Northwest's Cascade mountain range.
Small earthquakes had stirred the area for several months, and scientists
were warning of an impending eruption. But when an early-morning earthquake
rumbled through the area, it touched off an unexpected sidewards-pointed
explosion in the peak, sending ash, pulverized rock, and searingly hot
gases shooting out of the mountain slope to the north and west.
The explosion rearranged the landscape. It carved over 1,000 feet off
the top of the mountain, and gouged a mile-wide crater in its side.
Nearby trees were flattened, lakes, rivers, and streams were filled
with rock and ash, and many landmarks simply ceased to exist.
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Over 50 people were killed in the blast. In the days that followed,
much wildlife was killed as well, either in the initial blast
or by the sudden drastic changes in habitat that followed the
explosion. Over 7,000 large game animals died, according to forest
service estimates, along with thousands of fish. Some were smothered
by ash or burned by the blast. Others were kept out of their habitats
or away from food by the eruption.
Life began returning to the scorched flanks of the mountain almost
immediately. Just months after the eruption, hardy plants were
seen poking through the gray volcanic ash. Now, twenty years after
the eruption, many areas are green again. Insects and seeds drifting
in on the wind helped to recolonize the area. And though amphibians
around the world have been in decline in recent years, the amphibian
populations around Mt. St. Helens are doing extremely well.
What have scientists learned about volcanoes, and about wildlife
recovery after natural disasters in the 20 years since the eruption?
Tune in and find out on this hour of Science Friday.
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1981
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1983
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1987
photos by F. Valenzuela, USDA Forest Service.
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Guests:
Christine Colasurdo
Co-creator,
"Spirit Lake Remembered" Exhibit
Cowlitz County Historical Museum
Kelso, Washington
Author,
"Return to Spirit Lake: Journey Through a Lost Landscape"
San Francisco, California
Peter Frenzen
Monument Scientist
Mount Saint Helens National
Volcanic Monument
Amboy, Washington
Don Swanson
Scientist-in-Charge
Hawaiian Volcano Observatory
Hawai'i Volcanoes National Park,
Hawaii
Books/Articles Discussed:
Related Links:
Mt
St. Helens National Volcanic Monument
Cascades Volcano Observatory
Live
Volcanocam from the U.S. Forest Service
Hawaiian Volcano Observatory
USGS Volcano Hazards Program
A world volcano
map from Michigan Technological University
VolcanoWorld
International Decade for Natural
Disaster Reduction
Global Volcanism Program, based
at the Smithsonian
UN Volcano Mitigation
Team
Produced By: Karin Vergoth
Web Producer: Charles
Bergquist
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