A meizanologist's diary (11)

October 20: watching NHK’s weather feature over breakfast, we’re finally able to put some numbers on our observations. We’ve noticed how warm it is this October - how could we not? In our student days, October mornings used to be crisp, cold affairs out here in the Fukui countryside.

Autumn as it should be (Kurobe valley)

In those days, the leaves would already be red and gold up on Hakusan, frost pillars would be pushing out of the ground, and, if you didn’t look lively, you might be mugged by a sudden snowstorm. All that is unimaginable this year. There isn’t even a dusting of snow on Hakusan, the trees are still more or less green and the bears are still wide awake. As for snowstorms, you’re much more likely to be bitten by a viper.

Now NHK explains why. “Autumn has been shortened,” the announcer says. The average temperature in recent Octobers has been 1.9°C higher than the average temperature for the month during the 1980s. (I’m not sure whether he’s talking just about Fukui, or for the whole country.) Of course, recent Decembers have been warmer too, but by a lesser margin – only 0.9°C warmer than in the 1980s. The figures don’t look that alarming, until you consider that the world today is only a few degrees warmer, on average, than during the Ice Ages.

Exploring the moulin in the Kuranosuke coire

On another morning, NHK reports on a deep hole or “moulin” that has appeared in the Kuranosuke snowfield high up on Tateyama’s eastern flank. This is the first one that has appeared in these parts for eleven years.

The Kuranosuke snowfield
(photo: Tateyama Caldera Sabo
Museum)

The savants of the Tateyama Caldera Sabo Museum are shown boldly roping down into the shaft, taking measurements as they go. On the way down, they encounter a layer of shattered boulders, evidence of some ancient rockfall centuries ago.

“Moulin” usually refers to the deep blue pits that drain surface streams down into the icy depths of alpine glaciers. Several thousand years ago, there would have been a real glacier in the Kuranosuke corrie.

But a survey in the 1980s did discover hard-packed ice layers at the bottom of its permanent snowfield that were 1,700 years old. Let’s hope the moulin closes up again before that ancient ice is all washed away.