Area: Sunset Creek, Mt Aspiring National Park
Activity: Multi-day transalpine trip. Survived a significant fall.
Survivor: 20-year-old male
Date of Accident: Late afternoon, mid-April 2006
On the second day of a multi-day tramping trip into the Olivine Wilderness Area, a party of four was tramping from the head of the Beans Burn, aiming to cross the Barrier Range via the Merkyl Glacier Route, before descending to the Forgotten River. While they were progressing up the slope towards Brenda Peak, the weather conditions deteriorated, bringing rain that turned to snow. The addition of poor visibility and winds made the planned high-level route untenable.
The group was not keen to descend the slippery slopes back to the Beans Burn, due in part to a damaged crampon, but also because of disagreement among the party about the level of risk, and the perceived need to push on in the deteriorating weather. There was also an element or ‘risk-shift’ – a social psychology term for the tendency of people to make more daring (riskier) decisions when they are in groups than when they are alone. This is particularly true of young men, whose judgement does not fully develop until they are in their mid-20s.
Eventually, the group decided to descend to a terrace at the head of Sunset Creek, where they would climb out of the basin to reach the Forgotten River. The decent route was very steep, wet from rain, and consisted of snowgrass slopes interspersed with small bluffs. As the group descended through the final section of bluffs they donned crampons and used ice-axes to provide traction on the steep terrain. When nearing the bottom, one of the party slipped and tumbled approximately 100 vertical metres, stopping in the plunge pool of a waterfall.
During the fall, the crampons deeply lacerated the inside of his knee, and tore the anterior cruciate ligament. The tramper also suffered other bruises and lacerations. After activating their PLB, the party was evacuated and the injured tramper taken to hospital. After surgery and physiotherapy, he made a full recovery and continues to tramp.
Polarisation within the group led, in part, to the decision to descend into the creek. As individuals, the group members may have considered the decent too risky, but as a collective they talked down the risk and proceeded; a classic heuristic trap. Behind this was the desire to go on and not backwards, along with the desire to get out of the rain; a case of desire overruling judgement.
A heavy pack weight probably contributed to this accident. The tramper was carrying an overzealous amount of equipment, including a heavier climbing rope than was necessary. Wearing crampons on wet steep tussock gives added purchase, however crampons can ball up with dirt and have a tendency to suddenly catch in tussock, leading to overbalancing and a fall. This technique should only be considered as a last resort, or other less-steep routes taken.
This article was re-published from the June 2015 issue of FMC’s Backcountry magazine. To subscribe to the print version, please visit www.fmc.org.nz/aboutbackcountry.
The Backcountry Accidents Column, in one form or another, has been a feature of FMC publications since 1938. Read Shaun Barnett’s article on the history of the column to understand the thinking behind this highly regarded series of articles.