Posted on 02/02/2010 7:06:54 PM PST by Steve Van Doorn
Since January 17, 2010 Yellowstone has had the second largest swarm ever recorded. The swarms have been steady at about 10 miles in depth and they have subsided a few days ago.
In the past two days the depth has raised up to around 7 miles and in the past couple hours quakes vastly increased.
http://www.quake.utah.edu/helicorder/ymr_webi.htm
http://www.seis.utah.edu/req2webdir/recenteqs/Maps/111-44.html
Remember this doesn’t mean we will see an eruption and it most likely means a normal volcano. It is very unlikely we will see a caldera eruption.
But these changes are significant and cannot be over looked
Some history:
Since the most recent giant caldera-forming eruption, 640,000 years ago, approximately 80 relatively nonexplosive eruptions have occurred. Of these eruptions, at least 27 were rhyolite lava flows in the caldera, 13 were rhyolite lava flows outside the caldera and 40 were basalt vents outside the caldera. Some of the eruptions were approximately the size of the devastating 1991 Pinatubo eruption in the Philippines, and several were much larger. The most recent volcanic eruption at Yellowstone, a lava flow on the Pitchstone Plateau, occurred 70,000 years ago.
It is impressive to see the area. You can still see the lava flows in the San Luis Valley and the tuft all over.
http://en.wikipedia.org/wiki/San_Luis_Valley
OH yessss steve, I’ll read the post - duh. Next time why don’t you read to whom the primary post was in response to. You were pinged out of courtesy. Next time I’ll leave you off if that will make you feel better.
But I don't know the timing of the serge movement of the Magma in the caldera. I don't know when it will return to the west end of the caldera. At that point we will see another increase in quakes.
OK, get well soon. FYI this swarm has been going on for a number of weeks now since Jan 17th. Here are the latest summaries and interpretations of the swarm
http://www.seis.utah.edu/EQCENTER/PRESS/yell_press.htm#20100118
When magma starts to move, they’ll know first.
The magma serge is most likely at that point now. This is getting interesting.
YMR continues to have a lot of activity, just not at the level it was for several hours last night.
"Yellowstone Volcano Observatory scientists still consider that the swarm events are likely the result of slip on pre-existing faults and are not thought to be caused by underground movement of magma. Currently there is no indication of premonitory volcanic or hydrothermal activity..."
I would love to see how they came up with that.
steve, your enthusiasm is good, your science is a bit off. The quakes you are seeing recorded are not the type that identify the movement of magma, but are a general tectoinc type. Go to this site:
http://earthquake.usgs.gov/learn/glossary/?term=harmonic%20tremor
for an example of the seismic signature of magma on the move. these seismic waves are not present in Ystone.
Yes I did and posted it.
I would love to see how they came up with that.
These are people with hundred of man-years combined study of volcanos and seismic events. They may study aspects of rocks - but are not dumb rocks. As I posted above, there are no harmonic tremors or other types of seismic signatures to suggest anything other than what they've posted.
can not believe we are even arguing this point.
That visual is simply awesome! Thanks for sharing the information.
Now find the similar one in your picture. In fact my link and picture above are taken from the very image you posted - right there in the middle. The shorter, higher amplitude waves are not harmonic tremors.
But then don't take my professional word on it as a geologist - nor the professional word of those who have made it their career to study it.
The Helicorders and webicorders do not record harmonic tremors quite like that which we are familiar with via regular seismograph signatures.
These events are captured as such on a webicorder.
http://i710.photobucket.com/albums/ww109/volcanism2/alaska/REF_2009-03-26.jpg
Note before Redoubt's first large eruption in March and throughout Feb. of last year, harmonic tremors were more the norm than the swarms you see on that graph prior to eruption. The harmonics oscillated as well but you can clearly see their signature on the webicorder.
The first large one at the top of graph led to a medium size expulsion of ash and vapor. More importantly, a series of harmonics started the quake swarm right before the first large explosive event.
Here is a graph of Redoubt’s webicorders showing the start of the Harmonic tremor stage. The settings on the webicorder were high so they appear a bit differently than the ones in march, where they had actually lowered them due to decreased activity.
http://i280.photobucket.com/albums/kk171/volcanism/alaska/redoubt_30jan.png
As you can see quite different compared to seismos.
Not sure I understand your question, but the ash cloud will all eventually fall to earth. Don’t forget the sulfur and other aerosols which coming out by the cubic kilometer also.
Just put the ppatch on an elevator and keep it going up. Simple. :)
Yeh, right, sure ;)
I can see (given the quality of the image)I see what could be harmonics beginning at about 14:45 and continuing to about 17:19 with increasing sharp, short seisimic events superimposed.
The following makes a comparison between common seismic forms
Now the issue is whether or not the seismographs at Ystone are seeing magma moving or only tectonic quakes (or the very similar shallow volcanic quakes - both involve rock movement) - the evidence points to tectonics. With all the study of harmonic tremors since Mt. St. Helens, this is one wave form that would get the notice of the seismologists.
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