2 massive landslides on Joffre Peak change the face of backcountry destination
Landslide expert says slides caused by warmer temperatures and melting snow
Two significant landslides sent rocks and debris tumbling down Joffre Peak this week, leaving a stark slash on the mountain visible from Highway 99 northeast of Pemberton, B.C.
The area located about 180 kilometres northeast of Vancouver is popular among backcountry skiers, mountaineers and other outdoor enthusiasts.
No one was injured in the slides, something Brent Ward, co-director for the Centre for Natural Hazards Research at Simon Fraser University, chalks up to luck more than anything else.
"These large landslides can be catastrophic," he said.
"If this had happened later in the summer, when there's a whole bunch of people on the trails, we would've had fatalities."
Warmer weather causing slides
The first slide occurred Monday morning around 7:40 a.m, according to B.C. Parks. The debris spanned up to 850 metres in width and travelled about 5.2 kilometres.
The second slide, on Thursday morning, scarred the same side of the mountain.
Ward said weather patterns are among the causes.
Alpine permafrost helps to hold rocks in place, he said, and as it melts, the rocks become more susceptible to landslides.
"Remember the hot weather we had last week?" Ward said.
"That hot weather melts snow that's on the mountain which then accumulates in fractures of the rock. That's actually what triggered the landslide."
Aftermath of the slides
Photos of the aftermath of the slides circulated on social media, with many in the outdoor community expressing surprise and concern at the scale of the slide.
"The community just really cares about this area — it's a huge, impressive geological event in an area where there are a bunch of mountain enthusiasts," said Nicholas Zichy, who knows the area well and captured some of the photos of slides.
Several backcountry ski routes, like the Twisting Couloir and Central Couloir, were washed away in the slide.
"There's a lot of sadness in the community with many [ski] lines shutting down," said Zichy.
The Cerise Creek trail to Keith's Hut is closed because of damage from the slide and B.C. Parks has also closed the Nlháxten/Cerise Creek Conservancy because of safety concerns.
Joffre Lakes Provincial Park, a popular hiking and walk-in camping spot, wasn't impacted.
"There's an ongoing assessment," said Sarah Morgan, emergency program manager with the Squamish-Lillooet Regional District.
"For the backcountry and ski touring community, they are obviously very interested in how this will change the recreational opportunities."
B.C. Park staff are still evaluating the scope of the damage.