Mount 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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Washington Geologic Wonders: Dry Falls was really flowing during the last Ice Age

The Dry Falls formation in Grant County was created by massive flooding during the last Ice Age, 12,000-18,000 years ago. Photo: Rian Skov/DNR.

The majestic Dry Falls formation near Coulee City was created by the Missoula floods about 12,000-18,000 years ago during the last Ice Age. A cycle of damming and breaching of the ice surrounding Glacial Lake Missoula (a massive lake situated in current-day western Montana) produced numerous large floods. In their wake, the floods left the many large carved landforms (including Dry Falls) that we see today across parts of Montana, Idaho, Oregon, and Washington. The floods sculpted Dry Falls by cutting into the Columbia River Basalts rock formation. It is estimated that the volume of water coming over the falls during those Ice Age floods was about ten times greater than Niagara Falls.

This impressive spot is easy to visit and learn about, thanks to the Washington State Parks-maintained visitor center there. Dry Falls also is a principal stop along the proposed Ice Age Floods National Geologic Trail.

Learn more about the geology of Washington state by reading  Washington State Geology News, published by DNR’s Division of Geology and Earth Resources. Sign up for a free subscription

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DNR published report shows potential gaps in earthquake recovery

The strong earthquake that struck the Chinese province of Sichuan this weekend killing more than 180 people is a reminder of the earthquake risks we face in Washington state. Geologists say it is not a matter of ‘if’ but ‘when’ a major earthquake strikes our state.

A major problem that emergency planners face is how long should it take to rebuild infrastructure versus how long will it take? To get a picture of how well we are, or are not, prepared to recover from a large earthquake, DNR— home of the state’s geologic survey—worked with other members of the Washington State Seismic Safety Committee to publish the ‘Resilient Washington State’ report. The report contrasts optimum recovery times with best estimates of the reality. For example, hospitals in the greater Seattle area would need to be operational almost immediately after a major earthquake on the Cascadia subduction zone, but in reality some facilities might be seriously damaged and stay offline for months. The Resilient Washington State’ report offers recommendations to improve statewide resilience to earthquakes and other disasters.

This article from Washington State Magazine shows the challenges we can expect to face in western Washington following a major earthquake on the Cascadia subduction zone, which lies just off of our coast.

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Great Alaskan earthquake hit 49 years ago; effects felt in Washington State, too.

Large waves generated by the 9.2 magnitude Alaskan earthquake in 1964 destroyed this bridge in Washington State.

Yesterday (while we were intently focused on the aftermath of Whidbey Island landslide), was the anniversary of the March 27, 1964, earthquake in south-central Alaska that caused about 143 deaths. The magnitude 9.2 earthquake lasted for almost three minutes and caused widespread destruction to buildings, bridges and other infrastructure. In addition to hitting many  Alaskan coastal communities, tsunami waves generated by the earthquake took lives and destroyed property in British Columbia, Oregon and California, including 12 people in Crescent City, California, and four at Beverly Beach State Park in Oregon.

Here’s more information about earthquakes in Washington.

The Washington Emergency Management Division says the best way to survive any type of disaster is to have a plan, keep informed, and have a mobile survival kit. Find out if you are in a tsunami inundation zone. Download a tsunami evacuation brochure for your community. DNR worked with local governments to produce these brochures.

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Whidbey Island Coupeville Landslide

DNR geologist Stephen Slaughter photographs the newly exposed hillside at the site of the Whidbey Island landslide on March 27. Photo: Isabelle Sarikhan/DNR. More photos on Flickr.

LAST UPDATE: 6:25 p.m., 3/28/2013

Incident: Early in the morning on 3/27/2013, along Driftwood Way in the Ledgewood Beach Community in Coupeville, Whidbey Island, residents awoke to a noise that sounded like thunder or a sonic boom. A large landslide caused damage that was hundreds of feet wide. Initial reports are that seven homes were threatened and 17 more are isolated. No one was injured.

A Department of Natural Resources (DNR) Division of Geology and Earth Resources team is working with local emergency responders and the Island County Emergency Management Division to survey this landslide and understand the incident and its risks.

• 6:25 p.m. (3/28/2013): DNR geologists release their quick report on the Whidbey Island “Ledgewood-Bonair” landslide. View the full report here. 

  Key points from the report include:
  - The Ledgewood-Bonair Landslide (LB landslide) on Whidbey Island, Island County, Washington occurred around 3:45 am on March 27, 2013.
  - It is a small portion of a much larger landslide complex, approximately 1.5 miles long, that was prehistoric and may date back as far as 11,000 years.
  - The top of the landslide scarp averages 200 feet above sea level.
  - The landslide pushed (uplifted) the beach as high as 30 feet above the shore.
  - The toe (front of landslide at the beach) is slightly over 1,100 feet long and extends approximately 300 feet into Puget Sound.
  - Uplift of the beach is presumed to have been relatively slow (i.e., over a few minutes).
  - Wave and tidal action is actively eroding the toe with small sections (1-10 cubic feet) observed calving with the rising tide.
  - The volume of material moved was approximately 200,000 cubic yards (equivalent to 40,000 dump truck loads).
  - DNR geologic mapping from 2009 shows the extent of the landslide complex (Polenz and others, 2009, http://www.dnr.wa.gov/Publications/ger_gm68_geol_map_camano_24k.pdf).
  - Where observed, the access road has been shifted approximately 80 feet down vertically and to the west.

  

  The volume of material moved was approximately 200,000 cubic yards (equivalent to 40,000 dump truck loads).
  Photo by: DNR/Stephen Slaughter March 27, 2013

View previous updates and preparedness information. Read more…

Tohuku earthquake hit Japan two years ago; Deadly earthquake and tsunami are chilling reminders for Washington residents

At the Ocosta Elementary School near Westport, DNR hazards geologist Ray Cakir supervises undergraduate student assistants Ben LeVeque and Alec Cole as they take seismic survey measurements. Their work will add to a statewide data catalog of shear wave velocity profiles—an important factor in earthquake-resistant building design. Photo: Randall J. LeVeque.

Two years ago on March 11, a magnitude 9 earthquake, followed by a tsunami, hit northern Japan causing thousands of deaths and massive destruction to the nation’s infrastructure. An earthquake fault with similar potential lies just off the coasts of Washington, Oregon and British Columbia. Geologists say it is not a matter of ‘if’ but ‘when’ the Cascadia fault off our coast unleashes another mega quake. To get a picture of what we may need to do in the recovery, DNR and other members of the Washington State Seismic Safety Committee  produced the ‘Resilient Washington State‘ report. Some of the report’s conclusions and recommendations are mentioned by the Seattle Times in its Sunday edition).

Another look at what will someday happen here again (the last major earthquake on the Cascadia fault was  in 1700), comes from the February 2011 Christchurch earthquake that severely damaged New Zealand’s second-largest city, killing 185 people. That event, which left large parts of Christchurch in ruins, has valuable lessons for Seattle and other parts of western Washington might expect,  KPLU-FM reported recently.

The Seismic Safety Committee membership includes staff from the state’s Emergency Management Division, University of Washington, the U.S. Geological Survey, the Federal Emergency Management Agency, and private industry and professional groups as well as DNR.