Tuesday, December 20, 2005

Augustine volcano is still all steamed up!

Six more steam explosions were recorded Saturday on Augustine Volcano, but the island cauldron refused to yield its secrets to scientists who arrived by helicopter from Homer.

Dark clouds and rain obscured the upper reaches of the 4,134-foot peak, blocking access to a team equipped with an infra-red camera mounted on a helicopter. A second team in an airplane, hoping to measure gases in the air above the island, was similarly thwarted.

Dave Schneider, a U.S. Geological Survey volcanologist with the Alaska Volcano Observatory, was on an Augustine beach Saturday talking to his Anchorage office when he was told island seismometers were registering another explosion. But peering up into the inky sky, he heard and saw nothing.

Schneider had taken advantage of a break in the weather Saturday in Homer. He had hoped to see what happened to the seismometer near the summit, which shut down Thursday during a steam burst. His main purpose, however, was to get infrared data from the island. He knew there would be hot spots. He had hoped to look for new vents and fissures that might indicate magma moving toward the surface.

"Volcanoes are hot. That's not what we're after," he said when he'd returned. "We're looking for change in intensity over time."

Augustine, historically the most active volcano in Cook Inlet, began stirring last month. The mountain had significant eruptions as recently as 1964, 1976 and 1986.

With its array of seismometers, Global Positioning System satellite receivers and, thanks to Saturday's visit, a time-lapse camera, Augustine is one of the best-wired volcanoes in Alaska. Scientists have been especially interested to see the measurable swelling of the mountain -- by an inch, according to the GPS units -- coinciding with the recent sharp increase in ground tremors, Schneider said.

Augustine was also outfitted with a new ash collection system on Saturday, Schneider said. Scientists with ion probes and electron microscopes are eager to examine samples of ash blowing out the vents to see whether fresh magma is involved. The collection system consists of bright orange buckets purchased at Home Depot, left to collect whatever falls out of the sky in the coming days.

"Ash from a four-dollar bucket is going to get put in front of a half-million-dollar machine," he said.
With more bad weather in the forecast, scientists will continue to use remote sensors rather than eyes and ears to watch for any signs of an approaching major eruption.

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