Anatahan eruption intensifies, smog reaches Japan

Anatahan’s volcanic eruption escalated anew yesterday morning as indicated by increased tremor levels that were recorded in the government’s seismometer on the island.

The Emergency Management Office and the U.S. Geological Survey also said that volcanic smog from Anatahan has reached parts of Japan.

The EMO and the USGS reported two periods of increased seismicity yesterday morning. The first one occurred at about 6:47am and lasted about five minutes, while the second one began at about 9:19am and lasted about 10 minutes.

“Past periods of similar seismicity have resulted in eruptive ash pulses above 25,000 feet. However, satellite imagery is presently obscuring Anatahan, making it difficult to confirm ash heights,” the agencies said.

Tremor levels increased yesterday morning after temporarily subsiding following another strong volcanic eruption at past 10pm Wednesday. The EMO said the eruption spewed out ash to 42,000 feet at that time.

After heightened activity yesterday morning, the volcano mellowed down, with the EMO and the USGS describing tremor levels to range from 40- to 70-percent of the peak levels during the June 17-26 period.

Despite this, ash emissions appeared to continue. The last time the Air Force Weather Agency’s satellite monitoring detected ash was at 11:25am Thursday, according the EMO and the USGS. Those agencies said ash plume was visible at 20,000 feet and extended about 200 nautical miles south-southwest of the volcano’s summit.

Haze advisory for Saipan lifted

Gov. Juan N. Babauta yesterday lifted the volcanic ash and haze advisories for Saipan, Tinian and Rota.

The EMO said wind direction became easterly with the passage of a low-pressure trough.

“Volcanic plumes of dust and haze from Anatahan volcano are now shifting to the west of the Mariana Islands,” the EMO said yesterday.

But the EMO and the USGS jointly reported that a wide region of volcanic smog was detected over portions of Japan.

“A wide region of thin vog south of Kyushu, Shikoku, and western Honshu, Japan to 10,000 feet was apparent on visual imagery taken at 8:25am, UT (6:25pm, local time, Thursday),” the agencies said.

“This region begins about 460 nautical miles northwest of Anatahan and extends over 1,200 nautical miles to the northwest and 1,000 nautical miles north of the volcano,” they added.