Friday, January 02, 2009

Yellowstone Quake Swarm Update 7

The earthquakes continue again today for the sixth day at Yellowstone.  Since midnight there have been nine quakes, and three greater than 3.1 magnitude.  The webcorders continue to show near constant ground movement, and it is possible that there have been more than these nine reported events as the seismologist reviews have been taking a while with so many events to review.  As of this morning there are 330 quakes shown on the list since last Saturday, but I notice that events that occurred yesterday are being added today, and the Yellowstone Volcano Center indicated that there have been over 400 yesterday, so that number could be much higher.  This morning's two most recent quakes - a 3.6 and a 3.1 - were located right at the north end of the lake.  The last two quakes were not only larger than normal in the swarm, but they were even closer to the surface - .18 kilometers and .1 kilometers.  This very shallow activity is what has me wondering if there will be a hydrothermal explosion.

Norris Geyser Basin in Winter

From the US News blog on this event - quoting an email from a Splunk member who crunched the numbers:

"I'm sending you this email with some information I've gleaned from the USGS archives.  I'm analyzing the ANSS data ( in an install of Splunk, which is a timeline based search and reporting engine.  I have 30 years of data in the system, with about 2M quakes total. 
Using  the ANSS data, I discovered the number of 2.5 or higher quakes in the *general* Yellowstone area for the decade of the 1980s was 128.  The number of 2.5 or higher quakes for the region directly around the lake in the *last 4 days* was 30. 
Again, for 2.5 mag or greater quakes:
Entire region of Yellowstone for 10 years = 128 quakes
Area just around Yellowstone Lake last 4 Days = 30 quakes
The entire 1980s of 2.5 or higher quakes in the vicinity of the lake was a paltry 4 quakes.  Doing a quick back of the envelope calculation using the number of quakes and the intensities, the  activity over the last 4 days has released roughly 100x the amount of energy released in the entire 1980s for the same general region.  In the last week alone there have been 10 quakes of magnitude 3.0 or greater around the lake, with one as high as 3.8."


US News Blog discussing the past frequency of quakes

Illustration of the current Quake Swarm at Yellowstone

NEIC Earthquake List

Animation map

These show the webcorders just minutes ago - more jumps:

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Sunshine on Discovery Bay

Sunshine on Discovery Bay
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