Scientists Found a Glacier That Pulses Like a Heart

Added: 2026-06-01

[00:00:00]The ground isn't shaking. It's pulsing under your feet. [music] It feels like a steady heartbeat. But what would be beating deep inside a glacier? It's not an earthquake. And still, it can be connected to a landslide that can trigger a devastating tsunami and wipe out a few towns.

[00:00:19]For more than 5 years straight, scientists kept their eyes on Berry Glacier in Alaska. All because this glacier is kind of shaky. Back in 2020, a research team from the University of Alaska basically put an unstable area of Berry Glacier under a microscope. They set up sensors everywhere, hoping to catch the very first warning signs, the geological equivalent of a loud crack before something collapses.

[00:00:47]The thing is, [music] the ground was pulsing there. Tiny signals came and went, following a certain rhythm. No [music] one could understand the reason.

[00:00:59]The mystery lingered until one [music] day researchers realized the truth. The pulses turned out to be caused by water sneaking into cracks in the rock, freezing, thawing, and freezing again.

[00:01:12]It's like water wedging a door open little by little, and each freeze makes the cracks grow [music] just a bit more.

[00:01:20]Over time, all that pressure might become the final nudge that will cause the whole slope to crash. And that's why everyone's watching Berry Glacier and Berry Arm Fjord so closely. The mountain side there is steep, cracked, and unstable. It's basically a giant [music] stack of loose blocks held together by ice. If it suddenly gives way, millions of tons of rock could crash straight into the fjord below. That splash wouldn't [music] just make a few waves.

[00:01:52]It would be a massive disaster.

[00:01:55]That unstable slope at Barry Arm is sitting right above the water. If it lets go, it could send a powerful wave racing [music] across the water. For people out kaying or boating nearby, that alone would be extremely [music] dangerous. And in a worst case scenario, places like Whittier could see waves up to [music] about 7 ft high just from the initial impact.

[00:02:19]And that's not even the full nightmare version. If a huge chunk of the mountain collapses all at once, the wave right next to [music] the slide could be absolutely massive, hundreds of feet tall inside Upper Berry Arm and Heramman Fjord. It'd be literally a wall of water. That energy wouldn't [music] just stay there. Models show the tsunami could race about 30 miles down the sound and reach Whittier in roughly 20 minutes. Some estimates [music] put the waves there at over 30 ft high. Even if the real wave ends up smaller than the worst case models, [music] it would still be strong enough to cause serious damage.

[00:03:01]And it's not just towns at risk. A tsunami like [music] this could whip up violent currents and chaotic waves across the sound. This would put boats, cruise ships, and fishing vessels [music] in real danger.

[00:03:15]On shore, docks, harbors, and other coastal infrastructure in Whittier could take a heavy hit. The effects wouldn't [music] stop there either. Other coastal communities, including Chenga, Kitoch, Valdez, and Cordova could also feel the impact, depending on how the wave spreads.

[00:03:35]Tsunamis caused by landslides have already happened before, and they were devastating. For example, on May 18th, 1980, at 8:32 a.m., a huge eruption blasted [music] the north side of Mount St. Helens off. It turned out that magma had been creeping under the north slope, building a huge bulge. And when a [music] 5.1 magnitude quake hit right under the bulging side, the slope slid away at mindblowing speeds. That massive landslide, the largest on land ever recorded, tore down the mountain and smashed into Spirit Lake.

[00:04:15]All that rock displaced the water in a [music] giant wave. It was taller than a skyscraper. The wave crashed back into the lake, ripping up trees, stumps, and [music] debris, and creating an avalanche 295 ft tall. Some trees stayed intact, but most were sheared at the base by the super hot volcanic blast that followed seconds later. Most of the rubble traveled more than a dozen miles [music] down the North Fork Tout River, filling the valley with debris. It was similar to burying the valley in a wall of rock taller than the Statue of Liberty and then some more. At the end, a huge area was covered with rocks and mud. Spirit Lake ended up 200 ft higher than before because of all that debris.

[00:05:02]And even four decades later, floating mats of logs [music] still drift around the lake, pushed by the wind.

[00:05:10]But Alaska had an even crazier moment.

[00:05:13]It happened [music] in the evening of July 9th, 1958.

[00:05:17]That's when Latouya Bay got hit by a 7.8 to 8.3 magnitude earthquake.

[00:05:24]It happened on the fairweather fault and it triggered [music] a massive rock slide, crashing into the narrow inlet of the bay.

[00:05:32]The sound of the impact was heard from 50 mi away. All that rock splash sent a mega tsunami dashing through the bay, shredding trees, soil, and rocks to a height taller than the Empire [music] State Building.

[00:05:48]Miraculously, only five people lost [music] their lives, though many were injured. Two fishermen on a boat were taken by the waves. Two more, a captain and his 7-year-old son, got swept up in the tsunami, [music] lifted high into the air, and survived with barely a [music] scratch.

[00:06:06]Talk about a lucky break.

[00:06:09]The destruction didn't stop there. In Yucat, [music] the nearest town, bridges, docks, and oil lines got wrecked. A wave tower collapsed and [music] a cabin was flattened.

[00:06:21]Underwater cables that ran Alaska's communication system snapped. The mega tsunami wiped out forests along the shoreline, leaving almost nothing standing except a few trees on the northern and southern edges. The water carved a [music] damaged line almost 700 ft around the bay. It's still visible from space today.

[00:06:43]But let's get back to Berry Glacier [music] and the danger it poses. For a long time, scientists have been watching this [music] area the old school way.

[00:06:52]You know, planes flying overhead, digging through old photos and comparing notes from past studies.

[00:07:00]That stuff [music] helps, but it can miss tiny slow changes which are often the most important ones. And then satellites came into play. They allowed scientists [music] to add a powerful new tool called PS Insar. This is basically a way to spot ground movements so small you'd never see them with your eyes. This method is especially good at catching slow motion shifts where the land is not cracking, but creeping.

[00:07:30]Let's see how [music] it works.

[00:07:32]Satellites shoot radar waves down at Earth. Those waves hit the ground and bounce back up. The satellite times how long that bounce takes. If the ground is high, like a mountain, the signal comes back faster. [music] If it's low, like a canyon, it takes longer. If you do this again and again, you can tell if the ground has moved, even by just a tiny bit. Now, imagine the satellite doing this over and over as it circles the planet. Each pass adds another snapshot.

[00:08:04]Once you stack all those snapshots together, you get a superdetailed picture of how the land is changing [music] over time. The more passes the satellite makes, the clearer the story becomes.

[00:08:17]Using this method, researchers studied the Prince William Sound area with images from the Sentinel One satellite.

[00:08:24]They were focusing on months without snow, usually June through October, from 2016 to 2020.

[00:08:32]Then they compared all [music] that satellite data with older plane images and landslide records to see the changes. Satellites [music] can scan huge areas at once while still catching tiny movements. And because they keep coming [music] back to the same spot, scientists can track where the ground is shifting, how much it's moving, and whether that movement is speeding up or slowing down.

[00:08:56]The movement itself is called [music] displacement, and it's a huge clue.

[00:09:03]Lots of data points mean a clearer picture. It's like watching a time-lapse instead of trying to guess [music] using just a single photo. And since the land doesn't move at a steady pace, this helps scientists spot changes that could signal [music] growing danger. So hopefully we'll be able to catch it in time.