March 8, 2005
The Ongoing, Mind-blowing
Eruption of Mount St. Helens
Geological Society of the Oregon Country (GSOC) meeting
Portland State University
November 17, 2006
Dan Dzurisin
On behalf of colleagues at the USGS Cascades Volcano Observatory
U.S. Department of the Interior
U.S. Geological Survey
Let’s skip right to the good stuff
2004-2006
lava dome
East arm,
Crater Glacier
Feb. 22, 2005
whaleback
West arm,
Crater Glacier
1980-1986
lava dome
If this doesn’t quicken your pulse, check that you have one
It started on a quiet September morning…
…with an earthquake swarm…
September 23, 2004
…that didn’t stop!
September 24, 2004
SEP webicorder (on 1980-1986 lava dome)
Within a few days, several earthquakes were occurring per minute…
PDT
09/24
09/25
09/26
09/27
09/28
09/29
09/30
September 29, 2004
…and a large welt was rising on the south crater floor.
Eight days after the first earthquakes…
October 1, 2004
Mount St. Helens’ first eruption of the 21st century was underway!
By October 1…
Volcano advisory (10/6)
Steam and Ash
Volcano alert (10/2)
Tremor
Steam and Ash
Steam and Ash
Tremor
Steam and Ash
Volcano advisory (9/29)
Notice of volcanic unrest (9/26)
USGS and PNSN provided timely information and hazards assessments
to partner agencies and the public
On October 11, 2004,
the first new lava emerged
and the dome-building
phase of the eruption
was underway
Seismic Amplitude, September 20, 2004 – January 5, 2005
The eruption sparked intense interest
from the media and public
USGS scientists provided daily press briefings at CVO
until a joint information center was set up at
USFS Gifford Pinchot National Forest Headquarters
CVO kept its attention focused on the volcano…
The welt grew at a prodigious rate
(That’s a BIG helicopter)
October 7, 2004
2004 welt
1980-1986 dome
Until, on October 11…
October 11, 2004
…a hot (775°C, 1430°F) lava spine emerged
November 4
In late October, a whaleback-shaped extrusion appeared
A time-lapse camera on Sugar Bowl Dome
records the whaleback’s growth
(sometimes)
Scientists are using a combination of time-tested and
innovative techniques to study the eruption
Helicopter mounted
FLIR and video module
“Spider” – helicopter-slingable
volcano-monitoring station
Therethey’re
…and
are several
evolving!
species of spider…
Marvin
MARV Lander - Brain child of
Marvin Couchman, USGS/CVO
…and
the new
We’ve
placed
the on
1980-1986
dome…
…including
some
placesspiders
even aon
volcanologist
wouldn’t
go
“Whale rider”
spider
In the process, we’re learning a lot about …
Volcano-glacier
interactions
February 22, 2005
Dome-building
processes and hazards
“Bathtub rings”
record dome growth
Why bother?
(So what?)
Eruption
mechanics
1980-1986 dome
“Fault gouge” is dome rock pulverized by earthquakes
Volcano Studies: Challenges and
Opportunities for the 21st Century
•
•
Radar-interferometry satellites can monitor most of the world’s
volcanoes at centimeter-scale accuracy with high spatial resolution
and virtually complete areal coverage
Networks of continuous sensors, including seismometers, GPS,
strainmeters, and tiltmeters, can maintain constant vigilance even at
long-dormant volcanoes. In the United States, EarthScope
(USArray, PBO, SAFOD, InSAR?) is the most ambitious and
promising Geoscience initiative ever undertaken.
•
Autonomous, self-organizing sensor networks can provide essential
real-time information that is spatially and temporally dense in areas
otherwise inaccessible for reasons of logistics or safety. Such
networks can trigger event-driven data acquisitions by Earthobserving satellites, thus supporting continuous global surveillance of
hundreds of dangerous volcanoes. USGS/CVO, WSUV, and NASA are
developing a prototype system for deployment at Mount St. Helens.
•
By monitoring volcanoes more thoroughly using a combination of oldschool and 21st century techniques, scientists might be able to
anticipate the onset of shallow volcanic unrest, intensify monitoring,
and provide longer term warnings of impending eruptions.
Something EXTRAORDINARY is happening at Mount St. Helens.
The volcano’s last 2 quiescent periods lasted 123 years (1857-1980) and 18 years
(1980-2004). Past inter-eruption periods have lasted for several millennia.
We’re living in interesting times.
This is not
THE END!