Ontakesan Eruption: (Almost) One Week Later — News Reports Summary

Almost one week after the initial eruption, according to media reports the death toll on Ontakesan has reached 47 with 20 climbers still missing in what Asahi Shinbun and others have called “the deadliest eruption in Japan in the postwar period.” Others are still missing, but rain and volcano activity prevent rescuers and helicopters from searching the area.

The New York Times carries a first-hand report of the eruption from mountain guide Gaku Harada. “I thought it was the end of the world,” he’s reported as saying.

Former Prime Minister Junichiro Koizumi used the Ontakesan eruption to strengthen his argument against nuclear energy. The Asahi Shinbun reports him as saying “Even experts say they never expected Mount Ontakesan to erupt. Unexpected incidents can occur at any time… Earthquakes, tsunami and eruptions occur all over Japan so it must not have nuclear power plants.”

Ontakesan Eruption Update

Fatalities on Mount Otakesan

The list of fatalities on Ontakesan has grown to over 30 climbers, according to last night’s news in Japan and this English-language report. Apparently, most of the victims died of cardiac and respiratory problems after inhaling ash in the pyroclastic flow and ash cloud of the eruption itself.

Climbers and the Japan Meteorological Agency (JMA), which monitors 47 active volcanoes in Japan, had only about 12 minutes’ warning that Ontakesan would erupt. Apparently this type of eruption, a so-called phreatic eruption which involves steam rather than magma, gives few telltale warnings before blowing.

The Japan Meteorological Agency has put Ontakesan on a Level 3 alert, advising everyone to stay away from the mountain. Here’s the English-language volcano advisory webpage at JMA

Ontakesan Eruption

Ontakesan, Japan’s second-highest volcano, erupts in Nagano prefecture

Many hikers were on the slopes this weekend to view the koyo autumn leaves.

According to the news reports we saw on TV this morning, no-one was killed though several people were injured. Rescue workers were making their way up-slope even as some stranded hikers had started to make their own way down.

However, a more recent story from CNN reports that rescue workers have found 30 climbers “in cardia arrest” on the volcano, meaning they have no pulse but have not been declared dead by a doctor.

R. told me later in the day that hikers caught out couldn’t breath because of the gas, and that many started to write their wills.

Again according to those news reports, this may be the beginning of an active cycle for Ontakesan.