[Geysers] China quake effects?

[Lynn Stephens]

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> Date: Wed, 14 May 2008 14:29:03 -0700
> From: udo.freund at lmco.com
> To: geysers at lists.wallawalla.edu
> Subject: [Geysers] China quake effects?
> 
> I recall some discussion about an Alaskan quake a few years ago having several surprising effects on geysers in Yellowstone.  Since the early Monday (00:28:01 MDT) M7.9 quake in China there have been 46 aftershocks M4.4 to M6.0.  Despite this happening even farther away than previously "related" quakes has anyone considered if the recent odd activity may also be related?  Yellowstone's own activity map seems "normal" to "quiet".  The biggest is M2.1 about 9 hours prior to China's biggie.  Just guru geyser gazing from afar.
> 
> Thanks,
> Udo Freund


I should probably let Ralph Taylor respond to this since he was a co-author on the paper that discussed the effects of the 2002 Denali earthquake on Yellowstone geysers.  But, for those who are interested, here is some information about the effects the 2002 Denali quake had on Yellowstone.

Per the summary of their paper that appears on the University of Utah seismographic website:

22 geysers monitored

8 showed effects
10 no noticeable effects
4 too erattic to determine

8 changed
     5 increased--Daisy, Depression, Plume and Riverside, Pink
     3 decreased--Castle, Plate, Lone Pine


Here's (most of the) information from the University of Utah seismographic website about the effects of the Denali quake.  I've reproduced this because some of the newspaper accounts garbled the information, and some websites still have misinformation.

"Less than 18 hours after the Denali earthquake in Alaska, Smith and colleagues at the University of Utah Seismograph Stations reported the major jolt had triggered more than 200 small earthquakes in Yellowstone – something widely reported by news media in the days following the quake.

Smith now says the triggered quakes at Yellowstone numbered more than 1,000 within a week of the Denali quake – if the count includes tiny temblors that were not “located,” meaning their epicenters and depths were not determined. He says the quakes ranged in magnitude from minus 0.5 to just under 3.0. (Tiny quakes have negative magnitudes because modern seismic equipment can detect quakes smaller than was possible when the logarithmic magnitude scales were devised.)

Most of the triggered quakes were centered near geysers and hot springs."

“Several small hot springs, not known to have geysered before, suddenly surged into a heavy boil with eruptions as high as 1 meter [about 39 inches],” Smith and colleagues wrote in Geology. “The temperature at one of these springs increased rapidly from about 42 to 93 degrees Celsius [about 108 to 199 degrees Fahrenheit]” and became much less acidic than normal. “In the same area, another hot spring that was usually clear showed muddy, turbid water.”

Meanwhile, some geysers erupted more frequently than normal, while others erupted less frequently.

Yellowstone has more than 10,000 geysers, hot springs and fumaroles (steam vents), and scientists monitored how often 22 of the geysers erupted during the winter of 2002-2003. Eight of the 22 “displayed notable changes in their eruption intervals” after the Denali quake, 10 showed no significant changes and the other four were too erratic in the timing of their eruptions to determine if the quake changed them, the researchers wrote. Of the eight that changed:

-- Geysers that erupted more frequently following the Denali quake included Daisy, Depression, Plume and Riverside geysers in Upper Geyser Basin, and Pink Geyser in Lower Geyser Basin.

-- Geysers that erupted less frequently after the Denali quake included Castle and Plate geysers in Upper Geyser Basin and Lone Pine Geyser in West Thumb Geyser Basin.

Most geysers returned to their normal timing days to months after the Denali quake.

Oddly, geysers affected by earlier nearby earthquakes – most notably Old Faithful and Grand Geyser in Upper Geyser Basin – were not affected by the Denali earthquake.


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