The glaciers of Japan

A new discovery completes a century-old quest for lost ice-streams

That gully on Tsurugi always did look suspiciously like a glacier. As we toiled up its crevassed and stone-raked snows, we sometimes wondered if relics of ancient ice-streams might not lurk somewhere beneath.

It turns out that they do. Japanese newspapers report that three small glaciers have been found on Tsurugi and nearby Tateyama, in Honshū’s Northern Alps. Using a device known as ground radar, researchers from the Tateyama Caldera Sabo Museum detected patches of slow-moving ice underneath three snow-gullies on Tateyama and Tsurugi.

These ice-streams are about 27 to 30 meters deep and 400 to 1,200 metres long. This makes them comparable to many an icy remnant glacier in the European Alps. If Japan’s glaciers are confirmed as such, they would be the southernmost in all of East Asia.

The Tateyama researchers made their radar surveys between 2009 and 2011. In a sense, though, the search for Japan’s glaciers began more than a century ago. It started one summer’s day in 1902, when a young man in a well-tailored suit came striding over the summit of Shirouma and descended towards Japan’s second-largest snow valley.

Yamasaki Naomasa (1870–1929) knew exactly what he was looking for. He’d recently returned from Europe, where he’d seen glaciers and glacial landforms with his own eyes. In Vienna, he’d studied under the illustrious Albrecht Penck, who had invented the science of “geomorphology” and proved that four great Ice Ages had once rolled over Europe.

Within a hollow brimming with alpine flowers, Yamasaki found a geomorphological smoking gun – a huge red boulder grooved with long straight scratch-marks. To his expert gaze, it was as if an ancient ice-stream had just stepped up, bowed deferentially, and presented its calling card. The Shirouma Great Snow Valley had once held a glacier.

A few years later, Yamasaki came into contact with the nascent Japan Alpine Club. The scientist got on well with the club’s founder, the banker and writer Kojima Usui, and the two kept up a correspondence. They even met up in San Francisco during Kojima’s time as his bank’s representative on America’s West Coast.

Glaciers were of more than academic interest to Kojima. Signs of past glaciations bolstered his argument that the high mountains of Honshu were lofty and grand enough to be called the “Japanese Alps”. Not everybody shared his enthusiasm. Shiga Shigetaka, for one, would have preferred to call them the "Honshu Central Transversal Range".

In the end, Kojima got his way; Japan now has Northern, Central and Southern Alps. Meanwhile, Yamasaki prevailed against the naysayers who wanted to deny Japan its ancient glaciers. But nobody suspected there might still be relics of those ancient glaciers hiding out in deep snow gullies somewhere.

Today, Yamasaki’s memory is preserved in the name of a small corrie on Tateyama’s crater rim. Ironically, though, it wasn’t the pioneer glaciologist who identified this particular hollow as a glacial landform.

Perhaps the best tribute would be if the Tateyama researchers could take their ground radar to Shirouma for a scan of its Great Snow Valley (above). For what could be more fitting than to find another live glacier, this one flowing alongside Yamasaki’s original Red Rock.

References

Many thanks to Wes and Iain for alerting me to this story. Among the news reports are these:

Japan Times: First glaciers in Japan recognised

Nature in Japan blog/Mainichi Shinbun: Japan's first glacier discovered in Tateyama mountain range (with photo of location).

More about Japan's ancient glaciers here: The snows of yesteryear