A volcano just 100 miles from
Alaska's largest city has stirred back to life after nearly 20 years of
tranquility, sparking a round-the-clock eruption watch, seismologists said
Thursday.
The fresh wave of seismic activity at Mount Redoubt
suggests that the eruption could occur within days or weeks, the Alaska Volcano
Observatory reported.
Redoubt's renewed tremors sparked worries about
potential ashfall in Anchorage, where city officials advised residents to stock
up on supplies ranging from extra food and water to respirators, plastic bags
and windshield washer fluid.
Volcanic ash and mudflows spewed from Redoubt during its
last eruptive episode — a five-month stretch that began in December 1989. Those
eruptions created health hazards and cleanup headaches for surrounding
communities. The mudflows caused partial flooding at an oil terminal facility,
and the ash plumes disrupted international air traffic.
The long hiatus at the 10,197-foot peak came to an end
last fall, when seismic instruments registered an increase in activity. On Jan.
23, the levels increased markedly, leading the observatory to raise the alert
level for aircraft and emergency officials.
On Thursday, the observatory reported that the activity
was "largely unchanged with several volcanic earthquakes occurring every
hour."
The observatory's seismologists said the most probable
outcome would be an eruption "similar to or smaller than the one that
occurred in 1989-90 ... within days or weeks." A more explosive eruption
could send threatening mudflows or landslides down the Drift River and other
drainages, but that scenario was "much less likely," the observatory
said.
Observatory staff members are checking instrument
readings and satellite images around the clock to watch for temperature
changes, said volcanologist Dave Schneider. A Webcam was installed about 7.5
miles from the summit, and additional seismic equipment will be installed at
the volcano as weather permits.
Observers will also look to weather radar scanners near
the Kenai airport for help. Those scanners send data in six-minute intervals.
These scanners will be able to detect an ash plume should one appear, Schneider
said.
