Oberlin Times, fin collapse
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Rock Chunk Falls From Mount St. Helens
Staff and agencies
12 May, 2006
By PEGGY ANDERSEN, Associated Press Writer
SEATTLE - The sheer rock fin emerging in Mount St. Helens` crater lost about a third of its northern face recently, but because lava keeps pushing to the surface, the height remained the same Thursday — around 330 feet.
Bad weather had iced over scientists` cameras on the rim of the volcano, so the rockfall wasn`t recorded on film, he said.
"At that height, it becomes unstable and ... begins to collapse under gravity," he said. Boulders and finer rubble from the crumbling top surround the base of the fin.
The crater was formed by the southwest Washington volcano`s deadly May 18, 1980, eruption that killed 57 people and blasted about 1,300 feet off the then-9,677-foot peak.
The emerging rock takes different shapes, depending on what it meets at the surface.
The pace of the lava extrusion has slowed since October 2004, he added. For the past few months, St. Helens has been pushing lava to the surface at a pace of about 1 meter per second, down from 6 meters a second.
"St. Helen`s loves to build domes," he said. "It`s built many in its history and we suspect some of those went on for decades.
