October 1, 2004
By GENE JOHNSON
ASSOCIATED PRESS WRITER

SEATTLE -- A massive chunk of glacier in the crater of Mount St. Helens has fractured and started rising since a flurry of earthquakes there intensified, scientists said Friday.

The chunk, as long as five football fields and twice as wide, has risen as much as 11 yards above the rest of the 600-foot-deep glacier, said Jeff Wynn, chief scientist for volcano hazards at the U.S. Geological Survey's Cascade Volcano Observatory.

Likely, he said, something was acting as a piston, exerting pressure from underneath the glacier - possibly indicating an eruption in the next several days.

"We're saying there's a 70 percent chance of an eruption in the next several days to one month," Wynn said. "I personally would say it's higher than that, but that's the party line."

For the past week, scientists have detected thousands of earthquakes of increasing strength - as high as magnitude 3.3 - causing them to warn that a small-to-moderate eruption is likely. The ice apparently began rising Thursday afternoon, Wynn said.

Many trails and campgrounds near the mountain have been closed, but visitors hoping for a look at an eruption have flocked to the Johnston Ridge Observatory, which remained open five miles from the crater.

The glacier in the crater is the world's youngest, having developed since the St. Helens' devastating eruption on May 18, 1980. It forms a collar around a 1,000-foot-tall lava dome that grew in the crater during a series of minor eruptions that ended in 1986.

As the ice rose to the south of the lava dome, the dome itself lurched forward another three-fourths of an inch Friday morning, Wynn said, bringing the total distance it's moved to a little more than 3 inches since Monday.

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