Previous Story
2 earthquakes shake Northern Islands
|
Posted on Oct 07 2005
Two earthquakes with magnitudes of 4.6 and 4.7 occurred in the Northern Islands, but Anatahan’s seismicity remains at relatively low levels.
Citing a report from the National Earthquake Information Center, the Emergency Management Office and the U.S. Geological Survey said the 4.6-intensity quake occurred near Maug at about 9:28pm on Saturday last week.
A 4.7 temblor followed the next day between Anatahan and Pagan at about 4:50pm, the EMO and the USGS said.
The agencies added, though, that seismic activity on Anatahan remains at levels amounting to a few percent of peak levels recorded last June.
They said the volcano has not produced significant amounts of ash since volcanic activity took a lull in early September.
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 eruptions. The situation lasted only several days.
The volcanic activity displayed its strongest historical eruption last April 6, with the volcano spewing 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. (John Ravelo)
