Mount Asama Eruption Imminent, Japan on High Alert (Update)

There will be growing tension in central Japan tonight. Mount Asama, an active complex volcano, is stirring and Japan’s Meteorological Agency has put the region on high alert. Geophysicists predict the volcano could explode within the next 48 hours, possibly powerful enough to blast rocks from its peak, causing damage up to four kilometres away.

Mount Asama is infamous for the 1783 eruption that devastated the region straddling the Gunma and Nagano prefectures, killing 1,500 people. Since then, Asama has remained active, with a significant eruption in 1972. However, 2004 did see the volcano explode, ejecting volcanic material up to 200 km away, but very little damage was caused.

Building seismic activity in the area suggested an imminent eruption, prompting the authorities to raise the threat level to a 3 out of 5. A Level 3 alert means that there could be significant damage caused to nearby non-residential areas and a no-go zone has been imposed. This is the first time the Meteorological Agency has used the volcanic warning levels since they were adopted in December 2007…

“There are prospects for an eruption that could throw volcanic rocks to a distance of around 4 kilometres,” said Sadayuki Kitagawa, a senior coordinator for volcanic affairs at Japan’s Meteorological Agency.

All going well, the authorities have taken appropriate steps to safeguard the lives of people living in the vicinity of Mount Asama, a testament to the incredible science going into seismic prediction techniques. We can only hope damage will be kept to a minimum.

Update (1:15pm): An eyewitness account from Tony Gregson who lives 10 km from the Mount:

We live about ten kilometers south-east of Mt. Asama, and sitting at my desk at the unusually early time of six in the morning today, I briefly felt an unusual swaying sensation akin to the reverberations of a distant earthquake. A quick check of the earthquake sites disclosed no known (at the time) activity, and the response times on the sites I use are fairly quick.

For the last few days, I’ve noticed a surge in sulfurous odors, but when I mentioned it to some local friends this morning, they dismissively noted that the wind was blowing the “wrong” direction for these to have come from Asama-yama. (My take is that the fumes went up, over our heads, then back down and through our sinuses in a circular motion.)

But otherwise, the mountain looks just splendid caped in snow and puffing away like an old grandfather on his pipe!

—Tony Gregson

As @LouisS remarked on Twitter just now, there does seem to be a lot of activity around the Ring Of Fire these days. So lets have Johnny Cash sing us out…

Source: Reuters via @LouisS