AVALANCHE, HYPOTHERMIA, FROSTBITE

British Columbia, Coast Mountains, Mount Sheer

On Saturday, November 27, 1982, six youths and their adult leader were climbing Mount Sheer on showshoes. A total of 40 centimeters of snow had fallen during the previous two days and a few more centimeters fell on Saturday. Temperatures had been cold earlier in the week but had warmed to just below freezing as the storm came through.

The party had turned back and, at about 4 P.M., were descending an open slope that forms the top of a large west-facing bowl, just below the summit. As they moved down the slope, they triggered a 30-centimeter-high, 10-meter-wide, soft slab avalanche that carried them down about 200 meters into a shallow gully. Five members of the party were partially buried and two were completely buried. All extricated themselves or were quickly located and dug out, with the exception of Patrick Pattison (17), who had been near the bottom of the slope when it slid. After 20 to 30 minutes, Pattison was found buried under about 1.5 meters of snow. He was unconscious, with no apparent heartbeat or breathing.

The leader of the group immediately started CPR and asked one youth to descend and call for help on a radio that had been stored with some overnight gear lower on the mountain. Using a tarp, the others constructed a crude windbreak to protect themselves from the cold.

At 5 a.M. on November 28, a rescue party reached them and determined that Pattison was dead. The other youths were suffering from various degrees of hypothermia and frostbite but were able to walk out unassisted. They descended to Park Lane Lake where they were picked up by helicopter and flown to Britannia Beach. (Source: F.W. Baumann)

Analysis

The slope was concave and treeless, with a 30- to 40-degree inclination. Since it was snowing at the time of the accident, with restricted visibility, the hazardous nature of the slope may have been less apparent than it might otherwise have been. The presence of some depth hoar may have contributed to the instability. As a general rule, if suspect slopes steeper than 25 degrees have to be crossed, it should be done by one at a time.

The delay in the rescue party’s reaching the accident location was caused partly by a communications problem with the radio-telephone system and partly by some confusion as to which agency was coordinating the search and rescue operation. (Source: F.W. Baumann)