Yellowstone looks to be keeping everyone on their toes as we ring in 2009. The earthquake swarm reported earlier this week is continuing, with multiple events between 2-3.5 on the Richter Scale. Again, the folks monitoring the caldera – this time the Univ. of Utah – play down these events as normal for any active caldera system … and they’re very likely right. However, the media love to bring up the “supervolcano” angle and we’re even getting expert opinion from (wait for it) Garrison Keillor!. The earthquakes are just normal earthquakes so far – none of the dreaded/anticipated harmonic tremor that might indicate an eruption. This will likely mean that more gas and water monitoring will be occurring in the park in the coming weeks/months.
25 responses to “Yellowstone New Year’s Eve Update”
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Yes, the “Harmonic Tremor” was caused by two very distant 7.4 and 7.6 Indonesia earthquakes, it took 1/2 hour for the seismic waves to arrive at Yellowstone. They show up on all broadband seismometers across the US e.g. here in Tennessee.
http://folkworm.ceri.memphis.edu/heli_bb_ceri/CPCT_HHZ_ET.2009010312.gif
Any other similar low frequency (4 cycles/min) “Harmonic Tremors” are large distant earthquakes, not Yellowstone magma. I’m a bit embarrassed about an excited post I wrote elsewhere on the web. True Harmonic Tremors have a frequency of 0.5 to 5 Hz, not 1/15Hz! -
Just another amateur who has been watching the seismic traces during the last week. However, this afternoon, after everything quietened down for a day, there are what look to be well defined harmonic traces on many of the seismographs around Yellowstone from about 1.30pm to 4.30pm. Any comments on them? Two good examples (among many) are on Old Faithful and Madison River.
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whoops, I missed the reports on the two Indonesia earthquakes. They rang the YS caldera like a bell, at about a 4 cycle/min frequency. This might be the natural frequency of the caldera surface, if you think of it as a membrane stretched over a viscouse resonating chamber (my apologies to the physicists and acoustic engineers reading this blog, for my misuse of terminology).
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It looks like there was a steady harmonic tremor, for about 20 minutes or so, showing on most of the yellowstone sensors a bit bit earlier this afternoon.
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“It’s not far-fetched that almost everywhere in the world where you have volcanoes you have mythologies or new gods being created.”
~ Werner Herzog
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