Japan’s Active Volcanoes: Asahidake


The highest volcano on Hokkaido

At 2,291 meters, Asahidake in Daisetsuzan National Park is the highest mountain on Hokkaido – Japan’s northernmost island. It is actually an active volcano.

I climbed on and around Asahidake several times in the four years I spent on Hokkaido. But that was a while ago now: as in, before I got my first digital camera (for the record, a Sony DSC-R1, bought in 2007).

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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.