Featured Research

from universities, journals, and other organizations

Mount St. Helens Officially Slumbers -- Alert Level Goes Back To Normal

Date:
July 17, 2008
Source:
U.S. Geological Survey
Summary:
Scientists say the nearly three and a half years of eruption at Mount St. Helens is over for now and have lowered the volcano alert level from Advisory to Normal and the aviation color code from Yellow to Green.

Aerial view of Mount St. Helens' crater, as seen from the north. Note the two arms of the Crater Glacier in the crater foreground.
Credit: USGS photo taken on May 30, 2008, by Steve Schilling

Scientists say the nearly three and a half years of eruption at Mount St. Helens is over for now and have lowered the volcano alert level from Advisory to Normal and the aviation color code from Yellow to Green.

Mount St. Helens, which erupted violently in 1980, killing 57 people, reawakened in October 2004 when four explosions blasted steam and ash up to 10,000 feet above the crater. Scientists watched a spine of fresh hot lava pierce up through the bulging crater floor and growth of a lava dome continued until late January 2008.

"Five months have passed with no signs of renewed eruptive activity," said scientists at the U.S. Geological Survey's Cascades Volcano Observatory (CVO). "Earthquakes, volcanic gas emissions, and ground deformation are all at levels seen before the eruption began."

"We know that Mount St. Helens will erupt again in the future in some mix of renewed dome building and more explosive behavior. However, at this point, we can't forecast when the next eruption will begin," said Cynthia Gardner, Scientist-in-Charge at CVO. "USGS and the University of Washington's Pacific Northwest Seismic Network will continue to monitor Mount St. Helens closely for signs of renewed activity. Scientists expect that days to weeks of warning will herald the next time Mount St. Helens ‘wakes up' for another eruption."

USGS designates the level of activity at a U.S. volcano using the terms "Normal," for typical non-eruptive behavior; "Advisory," for elevated unrest; "Watch," for escalating unrest or a minor eruption underway that poses limited hazards; and, "Warning," if a highly hazardous eruption is underway or imminent. These levels reflect conditions at a volcano and the expected or ongoing hazardous volcanic phenomena.

From October 2004 to late January 2008, about 125 million cubic yards of lava had erupted onto the crater floor to form a new dome-enough to pave seven highway lanes three feet thick from New York City to Portland, Oregon. A comparable volume had flowed out to form the 1980s lava dome. All lava erupted since 1980 has refilled about 7% of the crater, which was created by the catastrophic landslide and eruption of May 18, 1980.

Even though the eruption has ended, some hazards persist. The new lava dome remains hot in places and capable of producing avalanches or minor explosions that could dust areas with ash up to 50 miles from the volcano. Rock fall from crater walls can produce clouds of dust that rise above the crater rim, especially during dry, windy days. Also, heavy rainfall or rapid snowmelt can send small debris flows onto the Pumice Plain north of the crater.

A weekly update of the status of all Cascade volcanoes, including Mount St. Helens, can be seen at http://volcano.wr.usgs.gov/cvo/current_updates.php. For more information about the 2004-2008 eruption, visit http://vulcan.wr.usgs.gov/Volcanoes/MSH/Eruption04/framework.html.

Additional information about volcanoes and volcano hazards is at http://volcanoes.usgs.gov/.


Story Source:

The above story is based on materials provided by U.S. Geological Survey. Note: Materials may be edited for content and length.


Cite This Page:

U.S. Geological Survey. "Mount St. Helens Officially Slumbers -- Alert Level Goes Back To Normal." ScienceDaily. ScienceDaily, 17 July 2008. <www.sciencedaily.com/releases/2008/07/080714112734.htm>.
U.S. Geological Survey. (2008, July 17). Mount St. Helens Officially Slumbers -- Alert Level Goes Back To Normal. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2008/07/080714112734.htm
U.S. Geological Survey. "Mount St. Helens Officially Slumbers -- Alert Level Goes Back To Normal." ScienceDaily. www.sciencedaily.com/releases/2008/07/080714112734.htm (accessed September 30, 2014).

Share This



More Earth & Climate News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Balloon Descends to Bottom of Croatian Cave

Raw: Balloon Descends to Bottom of Croatian Cave

AP (Sep. 29, 2014) An Austrian balloon pilot has succeeded in taking a balloon deep underground, a feat which he believes is a world first. (Sept. 29) Video provided by AP
Powered by NewsLook.com
Bodies Recovered from Japan Volcano Eruption

Bodies Recovered from Japan Volcano Eruption

AP (Sep. 29, 2014) Rescue crews finished recovering the remaining 27 bodies from atop Japan's Mount Ontake Monday. At least 31 people were killed Saturday in the mountain's first fatal volcanic event in modern history. (Sept. 29) Video provided by AP
Powered by NewsLook.com
Raw: Japan's Mount Ontake Erupts

Raw: Japan's Mount Ontake Erupts

AP (Sep. 27, 2014) A volcano erupted in central Japan on Saturday, sending a large plume of ash high into the sky and prompting a warning to climbers and others to avoid the area. (Sept. 27) Video provided by AP
Powered by NewsLook.com
California University Designs Sustainable Winery

California University Designs Sustainable Winery

Reuters - US Online Video (Sep. 27, 2014) Amid California's worst drought in decades, scientists at UC Davis design a sustainable winery that includes a water recycling system. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins