New lava lobe about the size of an aircraft carrier

By PEGGY ANDERSEN
The Associated Press

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After getting a good look into the crater, U.S. Geological Survey scientists said the new feature is about 900 feet long, 250 feet wide and 230 feet high.

"That sucker is huge," said Jeff Wynn, chief scientist for volcano hazards at the Cascades Volcano Observatory in Vancouver, about 50 miles from the southwest Washington mountain.

It's still growing, he said today, and glows red-hot at night.

Seismic activity is diminishing and "does not seem to correlate with how much material is coming out," Wynn said.

Earthquakes at the volcano are well below magnitude 1 and occurring at a rate of three or four per minute, said Bill Steele at the University of Washington seismology lab in Seattle. That's been the pace for about three days.

USGS scientists managed to collect some rock samples from the new lava lobe on Wednesday, using a bucket dangled from a helicopter on a 100-foot line.

"No one is allowed to walk in there," Wynn said. Trails within a five-mile radius remain closed, as does the Johnston Ridge Observatory, 5 miles north of the 8,364-foot mountain.

Scientists with Advanced Ceramics Research have been hoping to test one of their 22-pound, remote-controlled drone airplanes that might be used to collect gas samples and other data from the volcano. However, low clouds today prevented a launch under Federal Aviation Administration rules, the Daily News of Longview reported.

Fifty-seven people were killed by the volcano's massive May 18, 1980 blast.

Like the old lava dome, formed in the six years after that devastating eruption, the new lobe is made of a type of volcanic rock called dacite, Wynn said. More than 63 percent silica, it tends to be sticky and viscous — and "more likely to trap gases and reach an explosive point."
 
Other types of lava, with less silica, typically flow more easily and are less explosive, he said.

The volcano rumbled back to life Sept. 23, with shuddering seismic activity that peaked above magnitude 3 as hot magma broke through rock. Molten rock first reached the surface on Oct. 11, marking the resumption of dome-building activity that had stopped in 1986.

A more explosive eruption, possibly dropping ash within a 10-mile radius of the crater, is possible at any time, scientists have said. - On the Net: Advanced Ceramics Research: www.acrtucson.com U.S. Forest Service volcanocam: www.fs.fed.us/gpnf/volcanocams/msh/images/mshvolcanocam.jpg AP-WS-10-21-04 2136EDT