Today is the 27TH Anniversary of the Mt. Saint Helens Eruption

Nearly 230 square miles of forest was blown down or buried beneath volcanic deposits.

Photo: USGS

(TOUTLE, Wash.) - At 8:32 AM Sunday morning, May 18th, 1980, Mount St. Helens erupted.

Shaken by an earthquake measuring 5.1 on the Richter scale, the north face of this tall symmetrical mountain collapsed in a massive rock debris avalanche.

Fifty-seven people were killed; and 250 homes, 47 bridges, 15 miles of railways and 185 miles of highway were destroyed.

Nearly 230 square miles of forest was blown down or buried beneath volcanic deposits.

At the same time a mushroom-shaped column of ash rose thousands of feet skyward and drifted downwind, turning day into night as dark, gray ash fell over eastern Washington and beyond.

The eruption lasted 9 hours, but Mount St. Helens and the surrounding landscape were dramatically changed within moments.

In all, St. Helens released an amount of energy equivalent to 27,000 Hiroshima-sized atomic bombs (approximately 350 megatons).

In 1982, the President and Congress created the 110,000-acre National Volcanic Monument for research, recreation, and education. Inside the Monument, the environment is left to respond naturally to the disturbance.

On May 18th, geologist Tom Pierson of the USGS Cascades Volcano Observatory will present two 25-minute slide talks in the observatory auditorium.

The talks will be presented at 1:00 PM and 3:00 PM.

Visitors to the Johnston Ridge Observatory have a rare opportunity to witness a volcanic eruption first hand and observe the heaped up and cracked glacial ice that is flowing north in the crater.

The Crater Glacier has been stacked up by the growing lava dome and is gradually surrounding the lava dome that formed between 1980 and 1986.

The ongoing eruption has provided scientists with an excellent opportunity to test remote monitoring equipment and ideas (hypotheses) about how volcanoes work.

In the months and possibly years ahead we will watch with interest to see what the future holds for the Pacific Northwest's youngest and most dynamic volcano.

Johnston Ridge Observatory is located at mile post 52 on State Route 504 (Spirit Lake Memorial Highway).

The visitor center is open from 10:00 AM to 6:00 PM daily. Today admission is free.

Starting on May 19th admission to the Monument visitor centers (Johnston Ridge Observatory and Coldwater Visitor Center) will be via a Monument Pass. Monument Passes are available at the visitor centers for $8 per adult, youth age 15 and under are free.