Twilight zone

Anatahan’s volcano erupted at 3:30am yesterday morning, spewing ash and gas up to an altitude of 50,000 feet—the highest historical level ever since the volcano’s first recorded eruption in March 2003.

The ash plume resulting from the eruption was so large that it plunged the Marianas region into darkness—a semi-twilight that had motorists driving with their headlights on and people waking up thinking that it was still very early in the morning.

“I woke up and was surprised, thinking it was still six o’clock. Then I realized it was already 10 o’clock and began to wonder what was going on,” said 23-year-old Jason Perez of San Vicente.

Ash and gas blown southwest by the strong winds covered Saipan and Tinian, preventing sunlight from penetrating the islands. Hazy skies and cloudy conditions were also experienced on Rota. Darkness persisted until around noon, when the skies began to clear up.

The gritty haze forced some people to wear gas masks to prevent breathing in the dust. All exposed surfaces were covered with a thin layer of coarse grain.

The Emergency Management Office said that seismic activity on Anatahan began to intensify at about 10pm Tuesday night. Increased ash was also noted by the Washington Volcano Ash Advisory Center through satellite before the eruption occurred.

When the volcano finally blew its top at 3:30am, both the Volcano Ash Advisory Center and the U.S. Air Force Weather Agency verified the plume reaching up to 50,000 feet

Officials have placed Anatahan Island off limits until further notice, advising aircraft to exercise caution and avoid coming within 10 nautical miles (18.4 kms) of the area.

AFWA reported that the ash plume was being blown east-southeast, while ash at 15,000 feet were blowing toward the southern Mariana Islands, extending more than 250 nautical miles.

Seismic activity remained low from 4am to 9am and surged again for about an hour—about half the intensity of the earlier eruption—before dropping again.

Before yesterday’s big eruption, the volcano had been spewing out ash in the last few days, intensifying beginning early Monday morning.

The EMO and USGS said, that the two-month peak, which was recorded at about 1am yesterday, had lesser magnitude compared with the year’s peak recorded last Feb. 2. Both agencies said that seismicity dropped dramatically after Monday’s peak.

They said steam and ash extended to about 200 kilometers, while volcanic smog reached at least 200 kilometers farther at altitudes below 8,000 ft. The agencies said ash and vog could have reached an altitude of 15,000 feet, but stormy weather obscured satellite monitoring.

Volcanic ash and haze advisory still in effect

At 4pm yesterday, the EMO received updated information from the National Weather Service in Guam indicating that the ash plume for Saipan and Tinian was clear “for now” as long as no future eruptions occur.

“The ash plumes will be blowing east to north east for the next few days,” the agencies said.

EMO director Rudolfo M. Pua, however, said during an interview that the volcanic ash and haze alert remains in effect and that residents should continue to follow instructions given in the advisory.

“NWS is saying that the plume in our area is all clear, but there are dust or volcanic ash that are already on island so that is still in the air,” he said. “So, for health reasons, the governor is still advising people to follow the advisory.”

Pua said the islands may also experience vog—volcanic smog—in the coming days.

“We don’t know to what extent; it depends on the conditions up north and the wind direction,” he said.

At the moment, Pua said that he has no plans of sending a team to Anatahan due to the dangers imposed by the erupting volcano.

EMO said it will continue to monitor the ongoing eruption and issue updated advisories as they become available.

Latest advisories are posted in the EMO Emergency Information Hotline at 322-0222 or 0220 or the agency’s website at www.cnmiemo.gov.mp/

Anatahan’s volcano 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. That eruption, which ceased by mid-June that year, deposited about 10-million cubic meters of material over Anatahan Island and the sea. The second batch of volcanic eruptions happened from April to June 2004.

The third historical eruption began on Jan. 6, 2005 and continues today.