[Geysers] June 2004 Quake unblocked distant geysers

[V]

Three geyser related news items to check out 
Enjoy!
Vicky

___ NASA also has a similar story here
http://www.cent.org/geo12/nasa1.htm

___ And be sure to look at Grand Prismatic
http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=16559

___ Quake unblocked distant geysers
By Dr David Whitehouse 
BBC News Online science editor
http://news.bbc.co.uk/1/hi/sci/tech/3769921.stm

Castle Geyser erupted less often after the quake

A major earthquake in Alaska in 2002 set off lots of 
smaller quakes in the Yellowstone National Park about 
3,000 km away, say scientists.

Within hours geysers in the park changed their eruption 
patterns, according to the journal Geology.

Researchers believe that earthquakes keep geysers alive 
by periodically shaking loose clogged channels.

The Alaskan earthquake was one of the strongest in North 
America in the past 150 years.


Thousand smaller quakes

Robert Smith, of the University of Utah, says his team's study 
shows that large earthquakes at great distances can have 
profound effects on the Yellowstone geysers.

"We did not expect to see these prolonged changes in the 
hydrothermal system," he said.

The geysers showed changes just a few hours after the shock 
waves from the 3 November Alaskan earthquake passed through.

More than a thousand minor local earthquakes were triggered 
by the shock waves, many of them near hot springs and geysers.

They altered water and steam pressure in the geysers, opened 
new channels and unclogged others.

In the study, the researchers looked at the eruption patterns 
of 22 geysers during the winter of 2002-3, noticing that 
eight geysers showed major changes.

One of them - Daisy Geyser - erupted more often but returned 
to its normal pattern after a few weeks.

The geysers Castle, Plate and Plume also displayed short-term 
irregularities that lasted for a few days.

Directed energy

"Several small hot springs, not known to have geysered 
before, suddenly surged into a heavy boil with eruptions 
as high as one metre," the researchers say.

"The temperature at one of these springs increased rapidly 
from about 42C to 93C and became much more acidic 
than normal.

"In the same area, another hot spring that was usually clear 
showed muddy, turbid water."

Scientists once believed that an earthquake in one location 
could not trigger earthquakes at distant sites.

That view was altered after the 1992 Landers Earthquake 
(magnitude 7.3) in California's Mojave Desert triggered a 
spate of quakes more than 1,200 km away at Yellowstone.

Professor Smith believes that the Alaskan quake focused its 
energy southeast towards Yellowstone meaning that the 
stresses rippling through the ground at Yellowstone were 
200-300 times greater than if the quake's waves were aimed 
elsewhere.


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