Mild eruption on Anatahan

Anatahan’s rumbling volcano spat out ash during a relatively small explosion Monday.

The Emergency Management Office cautioned residents of the Northern Islands yesterday about volcanic plume of dust and haze, as it was expected to move northeast last night toward the tropical remnant of typhoon Sonca.

“As the storm moves to the northeast tonight [Wednesday night], southerly winds will bring the volcanic plume northward,” the EMO said.

The EMO raised the volcanic haze advisory on Alamagan, Pagan and Agrihan. It advised residents to take precautionary measures, especially those with pulmonary illnesses, who should minimize outdoor exposure.

A report by the EMO and the U.S. Geological Survey said that seismicity on Anatahan has been increasing this week.

A small explosion occurred about 10am Monday, producing an ash cloud that moved west of Anatahan.

The agencies also reported a plume of ash and steam rising at altitudes below 10,000 feet and streaming about 185 nautical miles northwest.

A separate advisory by the Washington-based Volcanic Ash Advisory Center yesterday morning said that low-level ash extended roughly 485 nautical miles north of the volcano.

Seismic monitoring of Anatahan has been partially restored after Emergency Management Office staff flew to the island Friday to repair its only functional seismic station.

The EMO team that flew to Anatahan last Friday included geophysical seismic technician Juan Takai Camacho. Before the repair, Camacho said last week that all seismic stations that were installed on Anatahan to monitor the volcanic activity on the island have been malfunctioning, hampering the EMO’s monitoring capability. Two other seismic stations have malfunctioned earlier.

Last April 6, the volcano spewed about 50 million cubic meters of ash. The eruption sent clouds of ash to an altitude of 50,000 feet, resulting in the cancellation of international and domestic flights on Saipan and a mild ashfall.

The EMO continues to warn aircraft to avoid passing near Anatahan. Although the EMO said that the volcano is not currently dangerous to most aircraft within the CNMI airspace, it said conditions might change rapidly. It advised aircraft to pass upwind of Anatahan or beyond 10 nautical miles downwind from the island and exercise due caution within 10 nautical miles.