Previous Story
Tremor levels on Anatahan rise again
|
Posted on Aug 08 2005
Tremor levels on Anatahan intensified rapidly early yesterday morning, indicating another possibly strong eruption.
Satellite imagery, however, could not detect the level of ash plume, according to the U.S. Geological Survey and the Emergency Management Office. But they added that Washington Volcanic Ash Advisory Center issued an ash alert based on the high seismic activity.
The USGS and the EMO said a gradual increase in tremor levels began around 2:30am. Shortly after 5am, tremor levels rapidly intensified.
They said the high seismic activity persisted for about half an hour, “indicating a possibly eruptive pulse from the volcano.”
Although dense cloud cover obscured satellite monitoring, the agencies said the tremor levels surpassed peak levels recorded from June 17-26. Tremors of those magnitudes usually result in ash emissions to more than 25,000 feet.
The agencies said tremor dropped back to about 70-percent of the June 17-26 levels by 5:45am.
Before the increased seismic activity, the VAAC said a 20-nautical miles ash plume rose to 18,000 feet and extended to the west or northwest.
Last Wednesday, volcanic activity escalated and ash emissions reached an altitude of about 42,000 feet.
