Mouint St. Helens: The big blast was 33 years ago today

On the morning May 18, 1980, Keith Stoffel, then a DNR employee, took this photo while on a sightseeing flight over Mount St. Helens. It is the only known image of the initial eruption. Photo: Keith Stoffel (c) 2010.

The explosion of Mount St. Helens on May 18, 1980, produced a powerful blast that destroyed 230 square miles of national, state and private forest, and took 57 lives. Some of those who died from powerful shock waves and clouds of hot ash and superheated gases were several miles away. Others drowned when  lahars — mud flows – spilled down local valleys and river beds.

Today, a 110,000-acre area around the mountain is a National Volcanic Monument. The mountain has been a lot quieter since the events of May 18, 1980; several steam eruptions occurred in 2004, but caused no injuries or deaths.

DNR’s Geology and Earth Resources Division works with the U.S. Geological Survey and other agencies to monitor Mount St. Helens and the other active volcanoes in Washington State.

Read more about Keith Stoffel’s narrow escape from the mountain’s blast after snapping today’s photo, and learn more about the eruption on our Mount St. Helens information page.

More photos of Mount St. Helens are on the DNR Flickr page.

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Mount Rainier: Regional landmark is also nation’s most potentially dangerous volcano

The community of Orting, Washington, is built on top of 500-year-old lahar debris from Mount Rainier (rear). Photo: USGS.

May is Volcano Awareness Month in Washington State. On the eve of tomorrow’s anniversary of the May 18, 1980, eruption of Mount St. Helens, DNR Ear to the Ground has featured one of the state’s five active volcanoes each day this week. Today, the spotlight is on Mount Rainier.

Because of its elevation (14,410 feet), massive icecap, glacier-fed valleys, and proximity to Seattle and Tacoma suburbs, Mount Rainier is the most potentially dangerous volcano in the nation — it’s also ranked among the top ten most-most dangerous in the world. According to the US Geological Survey’s Volcano Hazards Program, there hasn’t been a major eruption on Mount Rainier in 1,000 years, but an explosive eruption (a la Mount St. Helens) isn’t the primary concern. Mount Ranier can generate huge lahars — rapidly flowing slurries of mud and boulders — even without an eruption. Avalanches caused by heated rock or volcanic gases can swiftly melt snow and ice and produce torrents of meltwater that pick up loose rock and become a lahar.

In its role as the state’s geological survey, DNR mapped the routes of past Mount Rainier lahars. The most destructive — and most likely — lahar routes are on the mountain’s north and west sides. A lahar here could feed into the Puyallup River valley where cities, towns and housing developments have been built on top of lahar deposits from as recently as 500 years ago.

DNR estimates that a moderately large lahar in the Puyallup River valley would cause $6 billion or more in damages to structures and other property. Large lahars of the past have reached Puget Sound via the Nisqually River Basin, Commencement Bay and Elliott Bay, including the ports of Seattle and Tacoma.

Have you given much thought to the potential of a large lahar from Mount Rainier? Has it influenced your decisions on where to live or work? Join the discussion on DNR’s Facebook page.

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Mount Baker: Tons of snow and ice atop a sleeping volcano

As the second-most glaciated mountain in the Cascades, an volcanic eruption on Mount Baker could produce deadly lahars in several populated river drainages. Photo: USGS.

Volcano Awareness Month and our countdown to the 33rd anniversary of the Mount St. Helens, May 18, 1980, eruption continue with a look at Mount Baker. The main hazards posed by this active volcano in central Whatcom County are debris flows and debris avalanches from its considerable glaciers and snowpack–events that can occur even without a volcanic eruption.

Mount Baker has been mostly quiet since the mid-19th century when several explosions were seen from Bellingham – a mere 30 miles due west. It perked up in 1975 with several large emissions of volcanic gases. As the second-most glaciated mountain in the lower 48 states, Mount Baker presents similar mudslide dangers as Mount Rainier (the mountain with the largest glacier cover in the lower-48 states).

It’s quiet… for now.  

Mount Adams: Majestic giant has been quiet lately but still poses a threat

Mount Adams as seen from Mount St. Helens in this aerial photo. Photo: USGS.

May is Volcano Awareness Month in Washington State. As we approach the 33rd anniversary of the May 18, 1980, eruption of Mount St. Helens, DNR Ear to the Ground is featuring one of the state’s five active volcanoes each day this week. Today the spotlight is on Mount Adams.

One of the largest volcanoes in the Cascade Range, Mount Adams has been less active during the past few thousand years than its neighbors (Mounts St. Helens, Rainier, and Hood). The most common type of eruptions over the long history of Mount Adams have been lava flows–streams of molten rock–which created a volcanic field that now covers about 500 square miles of the landscape in Skamania, Yakima, Klickitat, and Lewis counties and the Yakima Indian Reservation. Even if there is no eruption, landslides of weakened rock originating on the steep upper flanks of Mount Adams can spawn dangerous lahars, which are watery flows of volcanic rocks and mud that surge downstream like rapidly flowing concrete.

Here is the current alert status for Cascade Range volcanoes from the U.S. Geological Survey’s Cascades Volcano Observatory.

DNR and its Division of Geology and Earth Resources help map, monitor and educate the public, governments and others about geologic hazards, including volcanoes, such as Mount Adams.

Have you been to Mount Adams lately? Join in the discussion on DNR’s Facebook page.

Glacier Peak: A volcano that may be out of sight for most, but not out of mind

Glacier Peak viewed from the east. Photo: USGS.

May is Volcano Awareness Month in Washington State. In the week leading up to the 33rd anniversary of the May 18, 1980, eruption of Mount St. Helens, DNR Ear to the Ground is featuring one of the state’s five active volcanoes each day.

Tuesday, May 14, 2013: Glacier Peak. Located in a wilderness area in eastern Snohomish County, Glacier Peak is not easily visible from any major metropolitan centers, and so the hazards (and attractions) of this 10,451-foot peak may get overlooked. Yet, Glacier Peak has produced larger and more explosive eruptions than any other Washington volcano except Mount St. Helens. Glacier Peak is only 70 miles from Seattle, which puts it closer to the state’s largest metropolitan area than any volcano except Mount Rainier.

Eruptions of Glacier Peak have characteristically produced large volumes of volcanic ash and airborne pumice that could endanger the closest centers of population. The last major eruption of Glacier Peak was around the year 1700.

We want our awareness-raising about Washington State volcano threats to encourage preparation and not raise unnecessary alarm, so here is the very latest on alert levels for Cascade Range volcanoes from the U.S. Geological Survey Cascades Volcano Observatory.

DNR and its Division of Geology and Earth Resources help map, monitor and educate the public, governments and others about geologic hazards, including volcanoes.

Join our discussion on Facebook about your favorite volcano in Washington State.

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Explore DNR’s online portal to another world—the one beneath your feet—on Geologic Map Day

The Washington State Geologic Portal is an online tool to locate geologic features and resources.

National Earth Science Week (October 14-19) concludes today with a special focus on geologic mapping and its importance to society. Geologic Map Day aims to put the spotlight on the uses of geologic maps for education, science, business, and a variety of public policy concerns. For example, DNR’s Geology and Earth Resources Division maps areas in Washington susceptible to soil liquefaction and other hazards. These maps help planners, builders and citizens to better understand the potential risks that earthquakes may post to buildings, roads, utilities and other human-constructed features.

Another map — the online Shallow Landslide Hazard Map shows the latest risk levels for mudslide by county. Still in beta testing but available to view, this online map is a joint project between DNR, the National Weather Service/NOAA.

Or you can really dig down (sorry, pun intended) with DNR’s Washington State Geologic Information Portal. These interactive maps allow you to create, save, and print custom geologic maps for almost any location in the state. You can even search by street address if you want. You also can download map data for use in a geographic information system (GIS) from the portal, which features several ‘pre-loaded’ maps focusing on landslides, tsunami evacuation, geothermal resources, subsurface geology, Mount Rainier lahar hazards and more. Here’s a 2-page fact sheet explaining how to get the most out of the Washington State Geologic Information Portal.

DNR briefs Pierce County, Orting officials on Mount Rainier lahar hazards study

LEFT to RIGHT: Jody Woodcock, Pierce County Emergency Management Deputy Director; Hunter George, Pierce County Director of Communications; Kevin Phelps, Pierce County Deputy Executive; Pat McCarthy, Pierce County Executive; Keri Rooney, Director of External Affairs-Pierce County Executive’s Office; Mark Bethune, Orting City Administrator; Tim Walsh, DNR Chief Hazards Geologist; and Recip (Ray) Cakir, DNR Hazards Seismologist. Photo: Bob Redling/DNR.

Officials from Pierce County, including County Executive Pat McCarthy, were briefed Tuesday afternoon (July 31) on DNR’s latest estimates of the economic impact of a major lahar (volcanic mudflow) from Mount Rainier. DNR’s Chief Hazards Geologist Tim Walsh explained how the department used mapping and loss-estimation software to compute a potential of $6 billion in structural damages to Puyallup Valley communities from a large lahar.

Also attending the Tuesday afternoon briefing were Orting City Administrator Mark Bethune and Pierce County Deputy Executive Kevin Phelps.

Among the eight major drainages from the volcano, geologists consider the northwest side a likely origination point due to the many weakened rocks there — lahars can be caused by landslides and earthquakes as well as by volcanic eruption. The Puyallup River Valley also is the most populated of the several potential routes for a  major lahar from Mount Rainier.

Because lahar-related flooding has the potential to reach as far as Commencement Bay and Elliott Bay, including the ports of Seattle and Tacoma, community officials are paying close attention to hazard estimiates and plans to mitigate the potential losses to lives and property.

View online maps of likely lahar flows from Mount Rainier, including the locations of properties by street address, on the DNR Geology Portal’s Mount Rainier Lahar (Volcanic Mudflow) Hazards – Property at Risk map. Or download the full report: Loss Estimation Pilot Project for Lahar Hazards from Mount Rainier, Washington, which was funded by the American Recovery and Reinvestment Act.

DNR offers technical assistance, mapping, education and other assistance to citizens and government officials and planners on a range of subjects, including geologic hazards.

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Pierce County cable viewers get update about Mount Rainier’s volcanic hazards

Our recent release of a report estimating the potential property damage in the Puyallup Valley from a lahar (mudflow) generated on westside of Mount Rainier received wide media coverage. The coverage may help remind east Pierce County residents and the rest of us of the dangers we face in this region of volcanoes, earthquakes and other natural hazards.

An important piece of the awareness raising effort is a news story on Pierce County TV, which reaches thousands of cable tv subscribers in the county. The television report also can be seen on PCTVs YouTube site.

Additional media reports included:

• KPLU: When Rainier blows, volcanic mudflow could cost us $6 billion 
• Seattle Times / AP: Report: Some Rainier lahar losses could reach $6b (Story also appeared on CBS News, Seattle Daily Journal of Commerce, Wenatchee World)

For details check out our June 7 blog, Major Mount Rainier lahar would cause $6 billion or more in structural, property damage or download the full report

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