Previous Story
4.4-strong earthquake jolts Northern Islands
|
Posted on Sep 29 2005
A regional earthquake with a magnitude of 4.4 occurred in the Northern Islands, while Anatahan’s volcano continued to show signs of reawakened activity.
In a joint report, the U.S. Geological Survey and the Emergency Management Office said the regional quake was located between Agrigan and Pagan. It occurred on Sept. 20, two days after a 4.7-intensity temblor occurred south-southwest of Guam.
The agencies said seismicity on Anatahan remained at low levels amounting to a few percent of peak levels recorded last June. They said the volcano had not emitted significant amount of ash.
The agencies maintained, though, that long-period earthquakes continued to occur, albeit sparsely. The volcanic earthquakes indicate magmatic movement that may lead to another eruption.
The agencies noted no volcanic activity on Anatahan beginning Sept. 3, after about eight months of continuous eruptive activity. The situation lasted only several days.
The volcanic activity displayed its strongest historical eruption last April 6, with the volcano spewing out ash to 50,000 feet. The USGS and the EMO estimated the volume of ash emissions in that eruption at about 50 million cubic meters.
The volcano first erupted on May 10, 2003 after centuries of dormancy, with ash plume rising to an altitude of over 30,000 feet and covering over 1 million square kilometers of airspace above the Pacific Ocean. That eruption, which ceased by mid-June that year, deposited about 10 million cubic meters of material over Anatahan island and the sea.
