The Pulse Event

Glaciologist Naomi Ochwat expected a massive river of ice but found a shattered junkyard moving at speeds physics suggests shouldn't be possible.

[Speaker 1]: In February 2024, a glaciologist named Naomi Ochwat climbed into a research plane to fly over the Antarctic Peninsula. She was heading toward the Hektoria Glacier. On the maps, and in the historical records, this was a massive, structured river of ice flowing into the ocean. But when she looked out the window, the glacier wasn't there. [Speaker 2]: She described it as a "junkyard." Just a chaotic, mushed-up mélange of icebergs floating in the water. The structure was gone. The order was gone. It was just debris. [Speaker 1]: Ochwat knew from satellite data that Hektoria had been retreating. That’s why she was there. But seeing it with her own eyes confirmed something that the data was only hinting at. The glacier hadn’t just melted. It hadn’t just slowly pulled back. It had shattered. [Speaker 2]: We’re talking about a collapse so fast that in a single fifteen-month window, Hektoria lost twenty-five kilometers of length. That’s fifteen miles of ice, gone, in just over a year. [Speaker 1]: But inside that year, there was a specific window-a two-month period in late 2022-where the speed hit a number that frankly shouldn't be possible. [Speaker 2]: 0.8 kilometers per day. [Speaker 1]: That is the number we need to talk about. Half a mile, every single day. [Speaker 2]: For a grounded glacier-ice that is heavy enough to sit on the bedrock-that speed is effectively breaking the speed limit of what we thought physics allowed. [Speaker 1]: And that is the angle today. We used to think sea-level rise was a dial you turned up slowly. Hektoria suggests it can switch to sudden "pulse events" that our models struggle to predict. And if this mechanism is happening there, we need to know if it can happen to the big ones. [Speaker 2]: It’s Friday, March 6, 2026, and you’re listening to The Angle. [Speaker 1]: So to understand why this specific collapse is ringing alarm bells right now, we have to look at how we got here. Because Hektoria didn't just decide to fall apart in 2022. This was a setup that took decades. [Speaker 2]: Right. Hektoria is a tributary glacier. It used to feed into the massive Larsen B Ice Shelf. People might remember Larsen B-it’s the one that famously collapsed back in 2002. It was a huge news story. When Larsen B fell apart, the glaciers behind it, including Hektoria, started to speed up because the door was open. [Speaker 1]: But then, things got weirdly quiet. For about ten years, from 2011 to 2022, Hektoria stabilized. It looked like the worst was over. And the reason for that stability is this specific type of ice called "fast ice." [Speaker 2]: Yeah, the terminology is a little confusing here because "fast" doesn't mean speed. It comes from the Norwegian word for "fixed" or "stuck." Fast ice is sea ice that is physically attached to the coastline. It freezes in the winter, and in this bay, it stayed frozen through the summers. [Speaker 1]: Think of it like a bandage. Or a cork. You have this massive glacier wanting to flow into the ocean, but the bay is choked full of this thick, rigid sea ice. It creates back-pressure. It physically holds the glacier in place. [Speaker 2]: Exactly. It’s a mechanical brake. And for a decade, that cork held. But then we hit early 2022. The Antarctic Peninsula experienced a significant heatwave, both in the air and in the ocean. And that multi-year fast ice-that cork-finally broke out. [Speaker 1]: And once the cork popped, the…