Posted on 03/10/2005 1:26:20 PM PST by Strategerist
Mount Spurr Volcano, about 80 miles west of Anchorage across the Cook Inlet, has grown restless in recent months. Scientists at the Alaska Volcano Observatory (AVO) first noticed the unrest in early July when hundreds of small earthquakes occurred 3 to 4 miles beneath Spurr's summit. Aerial reconnaissance in mid-July and early August documented recent small flows of mud and rock and a recently formed “ice cauldron” in the summit ice cap. The ice cauldron is a collapse feature possibly caused by an increase in heat coming from deep beneath the summit. Using sensitive instruments, scientists flying around the volcano on August 7 detected small amounts of the volcanic gases in a plume from the summit.
Taken together, the observations indicate that new molten rock (magma) has intruded deep beneath Mount Spurr. In response, AVO raised the level-of-concern color code to YELLOW. Eruptions, however, do not always follow such activity. Most times the magma never reaches the surface but instead harmlessly cools miles beneath the ground. At this time, it is impossible to forecast whether the current activity will culminate in an eruption or slowly diminish.
Though current activity is centered beneath the summit, Crater Peak, a flank vent on Mount Spurr two miles south of the summit, was the site of a 1953 eruption and the three 1992 eruptions that deposited several millimeters of ash on Anchorage and other communities in Alaska. Crater Peak has been the source of all known eruptions from Mount Spurr for the last few thousand years.
AVO monitors unrest at Mount Spurr using a network of seismic instruments, satellite observations, periodic overflights, and ground observations. In response to recent events, AVO installed five new radio-telemetered seismic stations at the volcano that will permit more precise location of earthquakes and better recording of volcanic tremor, and three radio-telemetered GPS stations to detect swelling of the volcano as magma moves towards the surface in the days and weeks preceding any eruption. In addition to new monitoring instruments, periodic overflights will enable scientists to look for surface changes at the summit and Crater Peak and changes in gases escaping from the volcano. Several teams of AVO geologists have already visited Mount Spurr to assess current conditions and to examine past deposits for clues about what might happen in the future.
An eruption of Mount Spurr, if it occurs, will likely be preceded by further changes in activity. Earthquakes will likely increase both in number of events and size. As magma moves from beneath the volcano toward the surface, it will break surrounding rock and thereby trigger earthquakes along its path. Emissions of volcanic gases are likely to both increase in volume and change in content before an eruption begins. When magma rises into a volcano, it causes the earth’s crust to swell in response. This swelling is usually, but not always, very small, and is only detected with very sensitive GPS instruments. New instrumentation will monitor these changes.
By combining observations of earthquakes, volcanic gas emissions, ground swelling, and on-the-ground geologic investigations, AVO scientists can better understand what is going on at this restless volcano. From these observations, scientists can formulate an accurate forecast of the possibility of an eruption that could spread ash on Southcentral Alaskan communities and disrupt aviation and airport operation. AVO’s mission is to inform the public when the volcanoes are about to erupt, but it cannot prevent them from erupting. On average, a Cook Inlet volcano erupts every 8 years spreading ash on the surrounding communities. Even if current activity does not lead to an eruption, residents need to be prepared to deal with the eventuality of volcanic ash falling on their community. Instructions on how to prepare for ashfall can be found on USGS (http://volcanoes.usgs.gov/ash/) and the Alaska Division of Homeland Security and Emergency Management (http://www.akprepared. com/plans/mitigation/volcano.htm) web sites. The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.
It's getting dark, a little cloudy, can't tell what's going on at the webcam:
http://www.avo.alaska.edu/avo4/atlas/volc/spurr/spurr2004/index.html
Looks like there MIGHT be some sort of eruptive cloud there low to the mountain, then again, might be regular clouds.
I'm not a geologist.
But I did stay at a Holiday Inn Last night :-).
Nope! It's Bush's fault!
...Seems the whole Northwest part of the continent is active. Mt. Saint Helens to Mt. Spurr. The shaky side shaking again. Thanks for the post...
Unfrozen water and 102F fumeroles at 11,00 ft. that have melted through 70M of snow and ice? As a layman, I'd say we got ourselves a live one.
http://www.esa.int/export/esaEO/SEMUVXO256E_planet_0.html
Double volcanic eruption in Eastern Russia
Well, that's two volcanoes out of hundreds (including all the ones in Alaska.)
Mt. Veniaminof just stopped erupting, actually.
This was happening last year also.
http://www.freerepublic.com/focus/f-chat/1180675/posts
That was the beginning of seismicity.
What is (apparently) happening today seismically is the first time this has happened during this episode...continuous tremor...not just rock-breaking earthquakes.
Some quiet volcanos on the Russian landscape are acting up as well.
First, I want to state before anything else, that I am not wise in the ways of science. That being admitted...
You're normally the one who shows up to refute these things...if you're posting about this, I pay attention.
I doubt he's a brother either.
The more one gets involved in this kind of event, the more one sees that these events are not unusual in any way.
The flows under the mantle are changing, as they always have. That means corresponding changes in and above the mantle. C'est la vie.
These are two sites my son likes to watch.
http://www.volcanolive.com/volcanolive.html
http://volcano.und.nodak.edu/vwdocs/current_volcs/current.html
The AVO hasn't officially said anything about the seismicity today (their last update was last evening) so I'm reluctant to make the sort of "she's gonna blow!" post that I'm usually not thrilled with on FR.
But the webicorder does seem to indicate "real" activity (not activity from distant quakes, there are no trains nearby, I really doubt it's wind noise) that looks very much like the eruption traces from the Mount Saint Helens webicorder, or possibly like "harmonic" tremor (movement of magma.) Continuous tremor is pretty significant.
Mainly what I debunk are the apocalptikooks trying to portray normal activity as "earth changes" or a sign of the End Times or other such nonsense (In the grand scheme of things, even the Sumatran tsunami was perfectly normal and routine, of course.)
As the AVO notes, one of the Cook Inlet volcanoes erupts on average every 8 years. The last to erupt was Spurr back in 1992...it's been over 12 years.
The one interesting twist here is the activity is beneath the main vent that hasn't erupted in 5,000 years, not the subsidiary Crater Peak vent that has been the source of dozens of eruptions in the last 5000 years and the last eruption.
The volcanoes that are currently erupting on Kamchatka are volcanes that are rarely "quiet"...they're volcanoes that erupt a lot.
Hmmm..
Just looked at the weather there and there's a pretty big storm in the Gulf of Alaska...high wind advisory (50-70 mph) for high elevations.
The change in activity COULD just be wind noise.....
I will be following your thread on this story. If it could go off without harming persons or property, by all means, I sure hope it goes off--bigtime.
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