2002 Alaska Earthquake Altered Yellowstone's Geysers

[hatrack]

BILLINGS, Mont. - "A major earthquake that hit Alaska in 2002 set off a flurry of smaller quakes in far-off Yellowstone National Park and changed eruption intervals in several geysers, according to a new study.

Scientists say the Denali fault earthquake is believed to be the first in modern times in North America to trigger large-scale changes in geysers and hot springs so far away. The quake registered a magnitude 7.9 and hit in November 2002. "What's really kind of interesting ... is the recognition that large earthquakes at very large distances can have really profound effects on Yellowstone geysers, given the orientation of the waves and the amplitude of the particular earthquake," said Robert Smith, a geophysics professor at the University of Utah who worked on the study.

The lead author was Stephan Husen, an adjunct assistant geophysics professor at the university. The work appears in the June issue of the journal Geology. The study says changes in eruption intervals in several Yellowstone geysers began in the hours after the Denali earthquake.

"Intense swarms" of local earthquakes also occurred near hydrothermal systems that saw such changes, the study said. Within a week of the Denali quake, Smith said, more than 1,000 earthquakes, many of them tiny and near hot springs or geysers, occurred at Yellowstone. Researchers believe surface waves from the large earthquake affected geysers by altering water and steam pressure in underground systems feeding the features."

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[LARED]

1. Interesting

http://neic.usgs.gov/neis/eqlists/10maps_usa.html

The Denali earthquake was only the 9th biggest in Alaska's recorded history. I wonder why this effect was only recorded recently.


Damage from the largest - a 9.2 in 1964