“Is it even kayaking if you don't get hit by a tsunami?”
- 4 hours ago
- 2 min read
Alaska. 10th of August 2025. Just before 6am. Nicholas Heilgeist outdoor specialist and naturalist, woke up to the sound of water rushing past his tent. With two other friends, he was on a kayaking trip on Harbor Island, near the mouth of Tracy Arm Fjord in SE Alaska. Their tents were pitched high up, well above the high tide line, deep in the woods. To say that hearing water close to him was surprising is an understatement. The second tallest tsunami ever recorded in human history was happening meters away from them, taking with it most of their gear. Nick’s Instagram bio is now: “is it even kayaking if you do not get hit by a tsunami?”
best.bio.ever.
Little did they know at the time that the same wave hit the neighbouring island, Sawyer island, and ran up 481 meters, yes 481 meters, taller than Taipei 101!
60 miles away at the National Tsunami Warning Center in Juneau only a small 35cm rise was recorded. The real alert, luckily, came from the kayakers and a few boats. In Fairbanks, the same morning, research seismologist Ezgi Karasozen jumped on the mystery. Lucky coincidence (or simply great scientific intuition), she had been working on a new algorithm to detect landslides from seismic data as they produce a very distinct signature very different from that of earthquakes. A quick look at the data on Tracy Arm (which was outside of their automated system) confirmed that a massive landslide has just occurred. The next day, a US Coast Guard flight confirmed the location of the landslide.
This incredible story was analysed, peer-reviewed and published in Science Magazine a couple of weeks ago. The study, led by the amazing Dan Shugar Professor at the University of Calgary showed that more than 64 million cubic metres came crashing down the mountain, that is the equivalent of 24 times the volume of the Great Pyramid of Giza! It produced an earthquake the magnitude of 5.4, and the water kept sloshing back and forth for 36 hours. It is an absolute miracle that no one was harmed by this. The slide happened at 5:36am on a Sunday, no ships were in the area at the time.
So what is the bigger picture of all of this?
The landslide was probably connected to a rapid retreat of the South Sawyer Glacier, the ice pulled back removing the support holding the mountainside in place. A cascading impact directly connected to human induced climate change. According to Bretwood Higman and colleagues, the number of tsunamis generated by landslides in Alaska has been multiplied by 10 over the past decade!
The more we burn fossil fuels, the more we can create these terrible situations.
This is where adaptation without mitigation will never be enough. In the meantime, let’s continue funding research, and monitoring equipment for the early warning systems we so desperately need.
