MOUNT ST. HELENS – Part of the lava dome in Mount St. Helens’ crater has risen 10 to 30 feet in the past day, on top of 250 feet in the past week, U.S. Geological Survey scientists said Friday.
Earthquake activity remained low, however, indicating molten rock is moving upward with little resistance, volcanologist Jake Lowenstern said.
The south side of the dome has been rising for the past week and is now nearly as tall as the dome’s 1,000-foot summit.
Despite the swelling, scientists said there was no reason to raise the alert level around the 8,364-foot volcano.
There was an outside chance an eruption could shoot ash 15 miles into the air or higher, but there was no indication that any eruption is imminent or that one would be powerful enough to threaten lives or property, said Larry Mastin, a USGS expert in the physics of volcano eruptions.
There’s no way to tell when magma – molten rock – might reach the surface, the scientists said.
Clouds and rain obscured the mountain for much of the day Friday. Discouraged by the weather, fewer people drove up the mountain to take a look. The parking lot at Coldwater Ridge Visitors Center, the closest open vantage point for viewing the crater, was only half full at midday.
Since Sept. 23, thousands of small earthquakes have shaken the peak in the Cascade Range.
“Escalation of unrest could occur suddenly and perhaps lead to an eruption with very little warning,” officials at the Mount St. Helens Joint Information Center warned.
Closures around the volcano – including the Johnston Ridge observatory five miles north of the crater – remained in effect. Johnston Ridge is usually closed for the winter by the end of October.
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