Tuesday, December 30, 2008

Yellowstone Earthquake Swarm

Over the past several days, something that may just be very unusual has been occurring in ancient caldera in Yellowstone National Park.  Over 250 micro earthquakes have occurred during that brief time, and while earthquake swarms are not uncommon in themselves, either at Yellowstone or other volcanoes, several aspects of this current swarm make it unusual, and therefore very interesting.

First, the many small earthquakes are not only occurring rapidly, but they are occurring in a very small area, less than one kilometer across.  They are also happening in Yellowstone lake just below, and immediately around the location of a dome on the floor of the lake - discovered only recently. 

Second, the quakes are generally very shallow.  Several have been less than .3 kilometers from the surface, and the average depth is about 2.5 kilometers, which places them at about the same depth as the magma chamber that drives the geothermal engine at Yellowstone, fueling the geysers.

Third, the quakes are occurring within the caldera itself, while the smaller swarms of 1985, 1995 and 2004 all occurred outside the caldera, nearer to Hebgen lake.  It is very likely that the quakes are related to magma movement through the geophysical system at Yellowstone, but it seems to be unclear to scientists at this time whether the quakes are a precursor to some sort of eruption, or just a particularly active set of routine quakes.  said Robert Smith, a professor of geophysics at the University of Utah said that "they're certainly not normal", and added that "we might be seeing something precursory. "

In the past couple of years seismologists have inched closer to developing a predictive technique to allow warnings before eruptions.  This technique was used to prevent loss of life in the eruption of Popocatepetl in 2000.  It indicates that sometimes harmonic tremors and quake swarms can predict volcanic eruptions. 

Likely the swarms at Yellowstone are just a larger than usual magma movement event, and no eruption is imminent.  At least, we'd best hope so, because the world's largest supervolcano would almost certainly cause immeasurable destruction both in the area within 100 miles and indeed around the world.  Some links to follow the action:






Map showing earthquakes





Anonymous said...

Maybe the geophysicists and seismologists want to hop on board with quakefinder and install some sensors. Perhaps we can get some accurate reads of electromagnetic field changes to see if there really is going to be a "big one" at Yellowstone. I hope not and I know it is a highly active area. I have been to Yellowstone several times and am always impressed by its majestic beauty ~~ even when seeing it just a few months after the huge fire in the 90s. We can thank Teddy Roosevelt for creating the Nat'l Park System and knowing one day it would be the only nature some of us city dwellers get to experience with awe.

Michael Burt said...

I've been waiting for more from Dr. Smith as they analyze the patterns ofthe tremors, with an eye to some of the harmonic patterns that preceded other volcanic eruptons, but thus far there has been no comment. As has been the case each of the past three days, the total number of events has slowed at night, and increased throughout the day. Will the pattern resume tomorrow?

We have some family pictures taken just days after the Hebgen Lake quake, and as damaging as that one was, a large quake surely would be preferable to an eruption - especially a cataclismic eruption a thousand times that of Mt. St.Helens. I'll post more tomorrow if the tremors continue.

And, though TR didn't set aside Yellowstone, he did set aside a huge amount of land (so much that Congress tried to block him, and he began creating Natonal Monuments without Congressional approval) for future generations. Anyone who wants a reasonable, measured approach to environmental conservation would do well to read TR.

wcgillian said...

You have an interesting blog here Michael. What got you started in the direction of Paranormal?

Michael Burt said...

I've always been interested in a lot of different things - far more than I could ever be informed about. I have always liked a good scary story, and then over time found that I stayed in a number of places that were reputed to be haunted. I've even taken to requesting the room thought to be haunted in hopes of seeing something. Alas, ghosts must not find me as interesting as I find them, because I've never yet seen or heard anything.

Closest I came was an episode of sleep paralysis that I experienced for th first time the night after seeing the original "Amityville Horror". I did not then know that some parts of the brain awake more slowly than ohers and thought I must be unable to move because the Amityville entity was after me. Tuns out, of course, that the body paralyzes itself every night so we don't act out our dreams, and it take a second or two to come out of it. Anyway, I still find thinking about and reading about paranormal events and phenomena to be interesting.

By the way, if you are interested in the way science and the paranormal were closely entwined at the beginning of the 20th century, read THUNDERSTRUCK. It is a great book, and spends a fair bit of time discussing the way that the discovery of energy waves, sound waves, and various phenomena that couldn't be seen caused many prominent scientists to wonder what else they couldn't see or hear that was also real. Thanks for the comment. MB

wcgillian said...

Interesting reply and thank you. One day i will share a story with you that Art Bell shared with his listeners a few years ago, (2001.) It occurred while I a was a Sgt. with the Issaquah Police Dept. in Gilman Village. I am sure you would enjoy it.


Michael Burt said...

I'll send you an email - I'd love to hear the story. And thank you for your service in law enforcement. Our society doesn't express it's gratitude for the job our law enforcement officers do for us - so I try to make sure I do. Look for a note from me, I;d like to hear the story. MB

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