MOUNT ST. HELENS, Wash. -- The lava dome in Mount St. Helens' crater apparently is growing, possibly a new sign of an impending eruption, but a major explosion doesn't seem likely, a top volcano scientist said today. ADVERTISEMENT
"There seems to be some movement in the lava dome," said Jeff Wynn, chief scientist at the U.S. Geological Survey's Cascade Volcano Observatory in Vancouver, Wash., about 50 miles south of the mountain.
The pressure could come either from a buildup of gases within the 8,364-foot volcano, which erupted with devastating force in 1980, or from molten rock moving into the dome, Wynn said. The volcano began stirring again last week.
Seth Moran, a seismologist at the observatory, estimated the initial movement at 4 centimeters, about an inch and a half.
Wynn said the movement "sort of suggests that we're getting closer" to an eruption that could hurl rocks and ash a few thousand feet into the air.
