Alberta Premier Danielle Smith has demanded the unrestricted ability to build pipelines across provincial borders.Chris Machian/The Associated Press
Dan Shugar directs the Water, Sediment, Hazards, & Earth-surface Dynamics (waterSHED) Laboratory at the University of Calgary, where he is an associate professor in the department of earth, energy and environment.
During her first face-to-face with newly elected Prime Minister Mark Carney in March, 2025, Alberta Premier Danielle Smith issued a list of nine demands that if not met, would purportedly threaten a national unity crisis. Chief among those pleas was unrestricted ability to build pipelines across provincial borders.
Alberta’s Throne speech a few weeks ago reiterated the demand, specifically describing the government’s desire for a new pipeline to British Columbia’s North Coast.
Ms. Smith seems to have gotten her wish. The Globe and Mail reported on Wednesday that Ottawa and Alberta appear close to striking a deal that involves such a pipeline.
But B.C. Premier David Eby, along with coastal First Nations, remain vocally opposed to such a proposal, and are supportive of continuing the tanker ban off the North Coast, which would effectively prevent any pipeline.
The Major Projects Office needs to be careful with pipeline projects to tidewater. Besides the very real issue of climate change caused in no small part by combustion of fossil fuels, there are other important reasons to be apprehensive of a new pipeline to the West Coast and the associated increase in tanker traffic that would accompany it. In particular, there is an underappreciated risk of tsunamis, but not the kind that you may have heard about.
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While most tsunamis are caused by earthquakes, the largest tsunamis (in terms of wave height and runup on shore) are caused by landslides. This is primarily because when an earthquake-triggered tsunami occurs in the open ocean, the energy can travel unfettered in all directions resulting in a fast but short wave only a few tens of centimetres tall. When they approach land, the waves grow rapidly to perhaps a dozen metres.
Landslide tsunamis however, typically initiate in narrow, steep-sided glacially carved valleys called fjords that are common on Canada’s West Coast and southern Alaska. These spectacular coastal features tend to be hundreds of metres deep beneath the waves, with sometimes kilometres-high rockwalls above, which is why they are so popular with cruise ships.
Occasionally, those steep rock walls collapse and trigger very large tsunamis. The tallest tsunami ever recorded occurred in 1958, when a giant landslide collapsed into southeast Alaska’s Lituya Bay, resulting in a wave that overtopped a ridge more than 500 metres high (almost the height of the CN Tower, and two-and-a-half times higher than the Calgary Tower).
Similar events occurred in B.C.’s Kitimat Arm in 1975, Greenland’s Dickson Fjord in 2023, Alaska’s Tracy Arm in 2025, and a couple of dozen other locations in the past century. In fact, following the Dickson Fjord tsunami, the Government of Greenland advised against all marine traffic to that fjord owing to the risk of further tsunamis capsizing ships.
During the hearings for the proposed Northern Gateway Pipeline in 2012, Canada’s attorney-general sought permission to submit late evidence of previously unrecognized submarine landslides in Douglas Channel, where that pipeline would have ended. Using high-resolution sonar, scientists from the Geological Survey of Canada mapped the deposits of two very large landslides. More recent work by federal scientists has discovered nearly 100 landslides in Douglas Channel, with the largest being one of the biggest in Canada. Many of these landslides, if they occurred today, would almost certainly produce a very large tsunami, presenting a risk to any people, ships, or infrastructure in the fjord.
We now have superb high-resolution maps of the ocean floor for most of B.C.’s fjords, but not much in the way of active monitoring for submarine landslides like we do for earthquakes. Nor do we have a complete picture of the landslide hazard on the rock walls above all those fjords, though recent developments in satellite and airborne monitoring are getting us closer.
Canada is a leader in oceanographic instrumentation and scientific monitoring, with organizations such as Ocean Networks Canada and the Hakai Institute as exemplars. Should a new pipeline to Kitimat or Prince Rupert be considered by the Major Projects Office, it behooves them to seriously consider the very real risk posed by landslide-triggered tsunamis. And, if approved, it would be prudent to follow the advice of federal government scientists and install substantial monitoring equipment to provide early warning of slope instability and tsunamis, similar to those at Barry Arm in Alaska.
Without further study, it is difficult to forecast the likelihood of a hundreds-of-metres-high tsunami that could damage or sink an oil tanker on B.C.’s North Coast. But what is certain is that if one occurs, the potential for substantial harm – to landscapes, to wildlife, to cultures and ways of life – is high. Geology usually happens slowly, except when it doesn’t. It would be foolish to be unprepared.