- Hundreds of people were cleared from around Mount St
Helens in Washington state yesterday as the restless volcano's increased
activity prompted government warnings that a big eruption was imminent.
-
- The alert level was raised after a spout of steam and
a forceful tremor on Saturday indicated more seismic energy than at any
point since the top of the mountain blew off in May 1980, killing 57 people,
destroying 200 homes and coating much of the US north-west with ash.
-
- Geologists say that the impending eruption is likely
to be much smaller. Tom Pierson, of the US Geological Survey, said the
level-three alert followed the detection of low-frequency tremors, indicating
that magma was moving and "an eruption is imminent, or is in progress".
-
- But he said the risk was confined to the area directly
around the mountain. Hundreds of visitors at the closest building, the
Johnston Ridge Observatory five miles away, were asked to leave. Many people
are camping in the area hoping to see an eruption.
-
- Gale Norton, the US interior secretary, reported after
flying over the mountain that seismic activity had weakened the 1,000ft
lava dome that began forming in the volcano's crater after the 1980 eruption.
Stephanie Hann, a Geological Survey spokesman, said: "It's like a
big cork and the new lava will be pushing like a piston against that cork."
-
- Mrs Norton said: "The greatest concern at this point
is an ash plume and the spread of ash itself that might come from an explosion.
This is a concern for aircraft."
-
- The 1980 blast reduced the height of Mount St Helens
to 8,364ft from 9,677ft, devastated hundreds of acres of forest and buried
the north fork of the Toutle River in debris and ash up to 600ft deep.
-
- The volcano's last eruption in 1986 caused little damage.
-
- © Copyright of Telegraph Group Limited 2004. http://www.telegraph.co.uk/news/main.jhtml;sessionid=JNVTYSSE
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