Yellowstone geologist discusses supervolcano threat


By: ALLISON BATDORFF - Associated Press
CODY, WYO. -- Could a basalt flow erupt from Yellowstone National Park without warning? Yes, says geologist Henry "Hank" Heasler.

Could a Mount St. Helens-size eruption take scientists by surprise? No. Nor could an earth-destroying catastrophic supervolcano like the one in a recent BBC-Discovery Channel docudrama about Yellowstone, Heasler told a standing room-only crowd Tuesday.

"The bigger eruptions are, the more indications we have," said Heasler, a Powell native. "We would see a catastrophic event months to years before it would occur."

Technology is making the prediction of eruptions easier than ever in one of the world's greatest laboratories - Yellowstone National Park. Three-dimensional imagery of the "lava-lamplike blebs" under Norris geyser basin gives geologists a picture of what's bubbling beneath the surface.

To help monitor the park's volcanic activity, a 25th seismic station will be added this year. More aerial work and satellite imagery is planned for this fall. The number of GPS stations around Mary's Bay and West Thumb will double.

Meanwhile, the temperatures of 40 of the park's 10,000 geothermal features are constantly watched.

"We are trying to monitor closely," Heasler said during a presentation Tuesday at the Buffalo Bill Historical Center's Coe Auditorium.

For geologists, Yellowstone holds many anomalies that aren't fully understood, he said.

"The words you say most as a scientist in Yellowstone are 'I don't know,' " Heasler said.

Interest is surging in Yellowstone geology, even though most people believe the made-for-television "Supervolcano" was just another disaster movie, Heasler said.

"Instead of saying 'I don't know and I don't care,' people are now saying 'I don't know and I'm curious,' " Heasler said.

The movie was based on the Huckleberry Ridge eruptions that scientists believe happened 2.1 million years ago in the park. Since then, Yellowstone has seen two other catastrophic eruptions - one 1.3 million years ago and another 640,000 years ago.

One of these is 6,000 times larger than the Mount St. Helens eruption. Heasler illustrates this using a financial analogy.

"Most of us have written a check for $1,000. Six thousand times that is $6 million. I don't think many of us will ever cut a check for that amount."

But this is a "low frequency" possibility and "geologically, we don't know when another would happen, if ever," Heasler said.

On a day-to-day basis, Heasler is more concerned with keeping people safe from the existing geothermal dangers and monitoring the dynamic park's constant changes. The park had 1,293 earthquakes last year. There were 130 just during this past June. People don't even notice most of them, and the activity is considered normal.

He also keeps an eye out for the telltale signs of bigger doings: earthquake swarms and dramatic surges in ground deformation, gas emissions, steam explosions and hydrothermal activity.

All of these happened in Yellowstone in the past decade, but they haven't been in the same place, Heasler said.

"These need to be in the same area to signify a big eruption," Heasler said.

He also will work with local and state Homeland Security Offices in preparing a Volcano Hazard Plan in the next year or so.

"If something was to occur, there's no way the park would be able to handle everything," Heasler told Park County Homeland Security Coordinator Alex Gisoldi. "We would need your expertise."

http://www.nctimes.com/articles/2005...5_557_5_05.prt