Media Advisory: 10th Anniversary of the Mount St. Helens Reawakening and Eruption of 2004-2008

Posted: 24 Sep 2014 12:00 PM PDT

Summary: In the early morning hours of September 23, 2004, a swarm of small-magnitude earthquakes about half a mile below Earth's surface marked the reawakening of Mount St. Helens after 18 years of eruptive quiescence

Contact Information:

Liz Westby ( Phone: 360-993-8979 ); Leslie Gordon ( Phone: 650-329-4006 );

USGS scientist Cynthia Gardner examines fresh rock samples from the new growth on Mount St. Helens' dome. (High resolution image)

VANCOUVER, Wash.— In the early morning hours of September 23, 2004, a swarm of small-magnitude earthquakes about half a mile below Earth's surface marked the reawakening of Mount St. Helens after 18 years of eruptive quiescence. Steam and ash explosions on October 1 were followed by three years of lava extrusion that formed a new dome inside the crater. The lava dome pushed Crater Glacier aside, causing it to flow rapidly toward the front of the 1980 breach; flow continues today.

Scientists at the U.S. Geological Survey's Cascades Volcano Observatory and its partners used many techniques during the 2004-2008 eruption to monitor the volcano, including interpretation of seismicity, ground deformation, thermal imaging, and lava sampling. By monitoring Mount St. Helens, scientists are better able to understand the volcano's behavior, to assess hazards and potential impacts, and to provide timely warnings of future events.

What:	Media availability for interviews: Interview topics may include remembering the events of the volcano's dramatic reawakening 10 years ago this week, what scientists have learned from more than three decades research at Mount St. Helens, and evidence that the supply of magma beneath the volcano is recharging. Mobile cameras and recording devices are welcome at the Cascades Volcano Observatory. A new four-minute video highlighting monitoring efforts during the 2004-2008 will be available.
Who:	USGS-CVO scientists: Cynthia Gardner, geologist Dan Dzurisin, geologist Seth Moran, seismologist
When:	Thursday, September 25, 2014, CVO scientists will be available between the hours of 10:00 a.m. to 3:00 p.m. PDT, for media interviews.
Where:	USGS-Cascades Volcano Observatory, 1300 SE Cardinal Court, Building 10, Vancouver, Washington
RSVP:	To lwestby@usgs.gov if participating, along with an estimated time of arrival and duration of interview.