Washington's Hanford Reservation and nuclear plant may lie on faults

  • A suspected fault scarp -- seen where the soil slumps at the center of this image -- running through Washington's Wenas Valley could be part of an active seismic system.

    Bill Lascher
  • U.S. Geological Survey Paleoseismologist Brian Sherrod co-authored a new paper suggesting that eastern Washington’s earthquake risks have been dramatically underestimated.

    Bill Lascher
 

Updated 11/7/11

"You're going to see some really cool geology," Brian Sherrod says, running his finger across the screen of his laptop in the cab of his pickup.

Sherrod, a U.S. Geological Survey paleoseismologist with a salt-and-pepper mustache, tents his hands and interlocks his fingers, illustrating how seismic forces created the craggy hillsides and deep fissures of Washington's Yakima Fold and Thrust Belt. In the satellite map on his computer, the region stretching east from the Cascade Range's volcanoes to the Columbia River resembles an ocean of frozen waves.

Sherrod will spend this spring day  exploring the Wenas Valley, about 100 miles southeast of Seattle. He believes there's an active fault here, part of a not yet fully mapped system that he and six colleagues describe for the first time in a paper published in July.

Until now, the extensive seismic hazards of western Washington were treated separately from those east of the Cascades, which were thought to be smaller and farther from population centers. But the fault Sherrod is seeking appears to be part of an interconnected system underlying the Cascades, from Puget Sound to Umtanum Ridge and Rattlesnake Mountain, which loom above Hanford Nuclear Reservation and the Northwest's only commercial nuclear plant, the Columbia Generating Station. Should it span the mountains, it could mean emergency planners have significantly underestimated eastern Washington's earthquake risks. Longer fault systems -- and this would be a long one -- generally produce larger quakes, though they don't always rupture along their entire length.

Sherrod closes his laptop and heads down a rutted dirt road toward Umtanum Ridge's southern flank. He's excited and confident, like a treasure hunter sensing buried loot. "I'm looking for stuff that happened thousands, even tens of thousands of years ago," he says. "I go out and look in the rocks and dig in the dirt."

But he starts from the air, using tools that measure minute changes in elevation and sensors that reveal differences in rocks' magnetic properties. Such differences could result from earthquakes nudging distinct rock layers closer together. He'll visit the most likely faults, ruling out landslides or anything besides earthquakes that might explain the data. Then he'll dig trenches and look beneath the surface for telling details -- fossils from different climatic periods that appear in adjacent soils, for example. Such clues suggest ground movements that broke contiguous layers of earth. Geologists can pinpoint the breaks in time by comparing the age of the fossils.

Seismic monitoring has been done in the Northwest since only 1969 -- a blip in geologic time. Monitors have mostly tracked activity west of the Cascades, where a subduction zone quake like the one that devastated Japan earlier this year will likely strike someday. Unexpectedly strong shaking from a magnitude 6.8 quake near Olympia in 2001 prompted an effort to map the entire state's hazards. Still, USGS geologists concentrated first on surveying the more populated west side, largely ignoring the territory Sherrod is now exploring. "We were amazed by how little actual information there was dealing with the activity of these faults," Sherrod says. In the past three years, he's found at least three new faults east of the mountains -- and they are just the tip of the iceberg, he thinks.

"You think about the Cascades as being a big façade -- a big edifice that looks like it blocks (seismic activity)," Sherrod says. But he and his comrades have detected similar magnetic alignments on either side of the Cascades, some at depths indicating that the faults formed long before the range's volcanoes did. That suggests, Sherrod says, that they extend all the way through the mountain range -- a major shift in the geologic understanding of the region.

Further trenching and analysis of suspected faults is needed to determine just how significant the risk is, Sherrod says. In the meantime, emergency officials for cities and major infrastructure aren't rushing to update disaster mitigation plans, hazards maps and building codes. If Hanford and the Columbia Generating Station are at greater risk than previously thought, they may be forced to re-evaluate the adequacy of their plans. But John Schelling, earthquake program manager for the Washington State Emergency Management Division, says there needs to be greater scientific consensus before the state adjusts its planning and public outreach.

Sherrod is still trying to develop a more complete seismic survey of the region. Recounting run-ins with rattlesnakes and other perils encountered on his quest, he scrambles up a hill toward one likely fault. "Even when you know where they're at, sometimes they're really hard to find," he says.

High Country News Classifieds
  • SECLUDED COLORADO HIDEAWAY
    This passive solar home sits on 2 lots and offers an abundance of privacy and views while being only 15 minutes to downtown Buena Vista....
  • COMMUNICATIONS COORDINATOR
    Introduction: Grand Staircase Escalante Partners (GSEP) is a non-profit 501(c)(3) organization with offices located in Kanab and Escalante, Utah. We are committed to the conservation...
  • CARETAKER
    2.0 acre homestead needing year-round caretaker in NE Oregon. Contact [email protected] for details.
  • MEMBERSHIP MANAGER
    For more information visit www. wyofile.com/careers/
  • THRIVING LOCAL HEALTH FOOD STORE FOR SALE
    Turn-key business opportunity. Successful well established business with room to grow. Excellent highway visibility.
  • DEVELOPMENT DIRECTOR
    For more information, visit www.wyofile.com/careers/
  • STAFF ATTORNEY
    STAFF ATTORNEY POSITION OPENING www.westernlaw.org/about-us/clinic-interns-careers The Western Environmental Law Center (WELC) is a high-impact, nonprofit public interest environmental law firm with a 27-year legacy using...
  • PROJECT MANAGER
    Position Summary Join our Team at the New Mexico Land Conservancy! We're seeking a Project Manager who will work to protect land and water across...
  • SEEKING PROPERTY FOR BISON HERD
    Seeking additional properties for a herd of 1,000 AUM minimum. Interested in partnering with landowners looking to engage in commercial and/or conservation bison ranching. Location...
  • DIRECTOR OF PRODUCT AND MARKETING
    High Country News seeks a Director of Product and Marketing to join our senior team during an exciting chapter of innovation and growth. This individual...
  • WILDLIFE HAVEN
    Beautiful acreage with Teton Creek flowing through it. Springs and ponds, lots of trees, moose and deer. Property has barn. Easy access. approx. 33 acres.
  • ARIZONA CONSERVATION CORPS PROGRAM DIRECTOR
    Arizona Conservation Corps is seeking a Program Director in Flagstaff or Tucson
  • COPPER STAIN: ASARCO'S LEGACY IN EL PASO
    Tales from scores of ex-employees unearth the human costs of an economy that runs on copper.
  • EXPERT LAND STEWART
    Available for site conservator, property manager. View resume at http://skills.ojadigital.net.
  • CONSERVATIONIST? IRRIGABLE LAND?
    Stellar seed-saving NGO is available to serious partner. Package must include financial support. Details: http://seeds.ojaidigital.net.
  • CANYONLANDS FIELD INSTITUTE
    Colorado Plateau Natural & Human History Field Seminars. Lodge, river, hiking options. Small groups, guest experts.
  • WESTERN NATIVE SEED
    Specializing in native seeds and seed mixes for western states.
  • CHUCK BURR'S CULTUREQUAKE.COM BLOG
    Change will happen when we see a new way of living. Thinking to save the world.
  • COMING TO TUCSON?
    Popular vacation house, furnished, 2 bed/1 bath, yard, dog-friendly. Lee at [email protected] or 520-791-9246.
  • OJO CALIENTE COMMERCIAL VENTURE
    Outstanding location near the world famous Ojo Caliente Mineral Spring Resort. Classic adobe Mercantile complete w/living quarters, separate 6 unit B&B, metal building and spacious...