'Randomness and chaos': The invisible, unpredictable forces behind fatal rockfall

The Canadian Press

· Posted: Jun 21, 2025 3:36 PM EDT | Last Updated: 5 hours ago

Scientist Daniel Shugar says images of the aftermath of Thursday's deadly rockslide successful Banff National Park supply grounds of its origin — h2o flowing done the interior of the mountain.

"You tin really spot immoderate springs coming retired of the cliff and really coming retired precisely from the scar itself," said the University of Calgary prof of geomorphology.

He described however h2o from a water supra the cliff astatine Bow Glacier Falls had been seeping done rocks for decades earlier it yet provided capable unit to dislodge a boulder, triggering the rockfall.

"That water has existed since 1955," helium said. "So implicit the past 70 years, the h2o from this water (and the) glacier retreating has been trying to spell downhill done the cracks. It fundamentally provided the unit to dislodge the rock."

LISTEN | Geomorphologist offers penetration into rockslides

While the forces whitethorn person been gathering for years, Shugar and different scientists hold it would person been intolerable for Parks Canada to foretell oregon forestall the monolithic rockfall.

"Yesterday was conscionable a atrocious confluence of events wherever this chunk of stone fundamentally popped retired of the cliff," helium said. "And, you know, unfortunately, tragically, determination were hikers down below."

Experts agreed that portion grounds of erstwhile rockfalls is casual to see, predicting precisely erstwhile they volition hap is impossible.

Davide Elmo, a mining engineering prof astatine the University of British Columbia, said that looking astatine a stone look from the extracurricular doesn't amusement what's happening inside.

"Some radical mightiness inquire Parks Canada, wherefore didn't you bash thing astir it," said Elmo, who besides has a grade successful engineering geology and is an adept successful stone mechanics.

"Well, that benignant of rockfall cannot beryllium stopped."

He said the lone happening officials tin bash is to archer the nationalist astir the risks erstwhile they participate an country that mightiness beryllium prone to rockfalls.

"We cognize they volition happen. We don't cognize erstwhile they volition happen," said Elmo.

Witnesses reported rumblings and stones moving earlier a slab of upland broke escaped and rained boulders connected hikers below.

The rockfall occurred successful a scenic country adjacent to a fashionable trail. Looking ahead, Elmo said officials should enactment up a announcement successful the area, informing hikers to "minimize the time" spent successful that location.

"You tin instrumentality photos from a distance, but don't enactment nether the slope. That's the worst spot to be," said Elmo.

John J. Clague, an emeritus prof successful Earth sciences astatine Simon Fraser University, said that erstwhile helium looks astatine the Banff and Jasper landscapes, helium sees tons of cones marking wherever rockfalls person occurred successful the past.

"Predicting precisely wherever 1 is going to occur, unless you person immoderate anterior denotation that thing was going on, would beryllium precise tough." helium said.

Clague said rockfalls are communal successful the confederate Rocky Mountains, but astir are ne'er witnessed.

Thursday's descent progressive "people being benignant of successful the incorrect spot astatine the incorrect time," said Clague.

John Pomeroy, Canada Research Chair successful h2o resources and clime alteration astatine the University of Saskatchewan, said determination was nary aboriginal indicator from h2o levels successful Iceberg Lake, which feeds Bow Glacier Falls, that could person predicted the tragedy.

"There's a batch of randomness and chaos successful events similar a stone slide, truthful the conditions were possibly favourable to it, but that it happened was simply atrocious luck," helium said.

"And peculiarly happening astatine that clip of time erstwhile determination were radical determination was highly atrocious luck."

Pomeroy said that this year, the glacier started melting early, raising h2o levels successful Iceberg Lake earlier than normal.

"It's surely much hazardous due to the fact that of clime change, but it's hard to accidental that clime alteration caused immoderate peculiar event," helium said.

Clague said each glaciers successful Canada person undergone thinning and retreating amid the warming climate, and helium thinks this incidental is linked to clime change.

"Because rockfall successful that spot could not person happened until the look became wholly escaped of ice."