Over the course of the past two weeks, more than one-hundred mostly small earthquakes per day, on average, have shaken up a remote area of Yellowstone National Park in Wyoming. Researchers say that for the time being, the earthquake cluster is more of a cause of curiosity than alarm.
The earthquake zone is located about 10 miles northwest of the Old Faithful geyser, and is far from any road or community. The park is also relatively empty during the winter months. The swarms of earthquakes are relatively common, and a significant swarm was experienced there last year as well. Researchers say that it has shown little indication that it will build towards a larger event, such as a volcanic eruption that destroyed the Yellowstone region tens of thousands of years ago.
Scientists say that the current Yellowstone swarm does at least bear close observation due to its volume. As of Sunday, January 31, 2009, there had been 1,608 earthquakes at the park since January 17.
Henry Heasler, a coordinating scientist for the Yellowstone Volcano Observatory, said:
“We’re not seeing a pattern that is really discernible yet." He added that plans were in place to intensify observations in the case that the swarm continued for a long time or got larger. "We're ready to ramp up," he said, which would include using flights to monitor the area.
Researchers at the University of Utah's Seismograph stations track the Yellowstone swarms, and say that they thought it was a coincidence that another large swarm of more than 1,000 earthquakes ahd struck the park just about a year ago. At the time, it was the second largest cluster recorded. This year's swarm, however, has overtaken the No. 2 spot. The largest recorded swarm was in 1985, when 3,000 quakes struck over the course of three months.
Dr. Heasler revealed that researchers use the park's geologic features, such as Old Faithful, as indicators of the quake activity. They look for changes in water temperature, or mud plumes in hot pools that otherwise run clear. He says that this swarm does not appear to have affected any of those natural monitors, emphasizing that analysis was on-going.
Park visitors are encouraged to help with research by reporting to park officials if they felt the ground shake. In general, attention to earthquakes has increased since the Haiti eathquake. According to the U.S. Geological Survey, visits to their Earthquake Hazards Program website have increased fivefold since the quake, to more than one million visits
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