Eruption every 10 seconds

Volcanic eruptions on Anatahan island continue to escalate, with explosions reported to have increased by about 40 percent, according to a joint report by the U.S. Geological Service and the Emergency Management Office yesterday.

“The explosions have slowly increased in size by about 40 percent since they began, and they are now occurring once every 10 seconds,” the report indicated.

Anatahan is an uninhabited island located about 120 kilometers north of Saipan.

The report also indicated that the ongoing strombolian eruption is very similar to the previous eruption from April to July last year.

During an overflight of the island Friday, EMO’s Juan Takai Camacho said the volcano continues to spew pyroclastic rocks hundreds of feet into the air.

Camacho said the ash may again bury the island, which he observed to be regaining its greenery after over a million cubic yards of ash were deposited on the land and sea following a big eruption in 2003.

Another overflight has yet to be planned. During an interview yesterday, EMO director Rudolfo Pua said he does not think another would be necessary.

The latest report released by the Volcanic Ash Advisory Center in Washington, D.C. said the center could not determine the extent of ash plume from the volcano’s crater by satellite imagery due to obscuring clouds. However, the VAAC’s satellite monitoring last week showed the ash plume moving westward. No ashfall has been reported on Saipan so far.

Pua said that if eruption continues and winds blow toward the southern islands, ashes from the volcano would be expected.

“Maybe we’ll experience some,” he said. “Then the public should cover their water catchments containers, and those with respiratory problems should stay indoors and minimize outdoor activity.”

The third eruption of Anatahan began on Jan. 5, with occasional small long-period seismic events noted as early as Jan. 2, followed by harmonic tremors early on Jan 4 that increased in size through mid-day of Jan. 5. This came after months of extremely low seismic activities.

No large events or explosion signals are associated with the onset of the eruption.

A low plume of thin ash and gas up to 500 feet was reported by Guam tower on Jan. 6.

The VAAC reported a plume on Jan. 6 that was 60km long and 20km wide blowing westward.

The EMO and Office of the Governor has placed Anatahan off-limits until further notice, and stressed that although the volcano is not currently dangerous to most aircraft with the CNMI airspace, condition may change rapidly, and aircraft should pass upwind of Anatahan or farther than 30km downwind from the island and exercise due caution within 30-50kn of the island.

The volcano on Anatahan first erupted after centuries of dormancy on May 10, 2003, with ash plume rising to an altitude of over 30,000 feet that covered over 1 million square kilometers of airspace above the Pacific Ocean and reached Philippine jurisdiction.

That eruption, which stopped by mid-June that year, deposited about 10 million cubic meters of material over Anatahan island and the sea.

Washington Rep. Pete A. Tenorio is currently lobbying the U.S. Congress for funding that would ensure a reliable volcanic activity monitoring system.

Tenorio, in a letter to U.S. congressman Don Young dated Jan. 6, 2005, said the CNMI urgently needs funding for a comprehensive volcano monitoring system, not only for Anatahan but also for all active volcanoes in the Northern Marianas.