Sunday, May 15, 2005
Facts about Mount St.Helen's volcanic activity
It's currently at Alert Level 2, the second highest. This indicates heightened concern about potential hazard, but not an imminent life- or property-threatening event. Under current conditions, small, short-lived explosions may produce ash clouds that exceed 30,000 feet in altitude. Ash from such events can travel 100 miles or more downwind.
IS THE VOLCANO GOING TO ERUPT?
By geologic standards, the mountain has been erupting since October, but scientists aren't sure if another large eruption is coming. So far, it has emitted steam and a little ash. A major eruption could produce a flow of superheated rock and ash that destroys anything in its path, as in 1980. People downwind from the volcano may have to contend with ash that could spew as much as 60,000 feet high and threaten aircraft.
HOW CAN SCIENTISTS PREDICT ERUPTIONS?
Scientists look for clues in changes registered by seismic and other monitoring devices; Mount St. Helens is one of the world's most closely monitored mountains. Federal agencies also have dispatched airplanes to take air samples. GPS monitors measure bulges and other changes in the mountain's lava dome and flanks that may signal an impending eruption. Weather stations forecast wind that would steer ash clouds.
CAN PEOPLE VISIT THE VOLCANO?
The mountain can be viewed from several places, including Coldwater Ridge Visitor Center, about seven miles away, and the Johnston Ridge Observatory, five miles away, which has a stunning view into the crater. Some area hiking trails are closed and restrictions are posted as well.