Towering over the northern side of Rusutsu Resort (Rusutsu Village, Shiribeshi region), Mt. Shiribetsu (1,107 meters) is a prime destination for many mountain skiers and snowboarders for its powder snow. It is popular for viewing the nearby Mt. Yotei (1,898 meters) and skiing the steep slopes that are largely free of trees, but snowslide remnants and snow cornice cracks have dotted the area.

On February 11, following several days of no substantial snowfall, I entered Mt. Shiribetsu from the west side to enjoy mountain skiing. After about 30 minutes, a massive, treeless slope with a height differential of 350 meters came into view. It was so impressive, it looked like a ski resort slope. However, on the left side as seen when facing the slope, bare ground from a snowslide was visible.

On this large slope, a surface snowslide occurred in January 2010, and one mountain skiing tour participant died. At the time, a snowslide and heavy snowfall warning had been issued for the entire area.

The ridge line extending towards Mt. Shiribetsu is lined with jutting snow cornice spots. Some of these leaning snow ledges have broken off under their own weight, forming large snow clumps. On the slope directly under, numerous ski tracks can be seen.

The numerous steep, treeless slopes of Mt. Shiribetsu may have been formed from repeated snowslides before trees could thrive there. When hiking in the area, it is important to thoroughly check the weather and bring equipment to find people caught in a snowslide, such as an avalanche beacon (electric signal transceiver), avalanche probe (search pole), and shovels.

(Words and photo: Kobayashi Motohide)