In a record-breaking event, Antarctica’s Hektoria Glacier lost nearly half its mass in just two months.
A glacier on the eastern side of Antarctica has undergone the fastest retreat ever documented in modern times. In only two months, nearly half of the ice vanished.
According to a new study led by the University of Colorado Boulder and published in Nature Geoscience, the Hektoria Glacier lost about eight kilometers ( 5miles) of ice in early 2023. Researchers found that the glacier’s collapse was driven by its unusually flat bedrock, which allowed it to start floating once it thinned significantly. This shift set off a rapid and uncommon calving event that caused the glacier to break apart.
The discovery offers scientists a new way to pinpoint glaciers that may be at risk of similar rapid retreats. Although Hektoria Glacier covers just 115 square miles (about the size of Philadelphia), experts warn that comparable events on larger Antarctic glaciers could have severe consequences for global sea level rise.
Witnessing the Aftermath
“When we flew over Hektoria in early 2024, I couldn’t believe the vastness of the area that had collapsed,” said Naomi Ochwat, lead author and CIRES postdoctoral researcher. “I had seen the fjord and notable mountain features in the satellite images, but being there in person filled me with astonishment at what had happened.”
Hektoria Glacier on Antarctica’s Eastern Peninsula experienced the fastest retreat recorded in modern history—in just two months, nearly 50 percent of the glacier disintegrated. This video illustrates how and why Hektoria Glacier retreated so rapidly in late 2022 and early 2023. New CU Boulder-ledresearch shows the main driver was underlying flat bedrock that enabled the glacier to go afloat after it substantially thinned, causing a rare rapid calving process. Credit: Lauren Lipuma/CIRES
The research team, which included CIRES Senior Research Scientist Ted Scambos, had been studying the region around Hektoria Glacier using satellite imagery and remote sensing for an unrelated project. Their goal was to investigate why sea ice had detached from a nearby glacier roughly ten years after an ice shelf collapse in 2002. During this analysis, lead author Naomi Ochwat discovered surprising data showing that Hektoria had almost completely vanished within just two months.
Determined to find out what caused such an abrupt change, she began a new investigation to uncover why the glacier retreated so rapidly.
The Role of Ice Plain Topography
Many glaciers in Antarctica are tidewater glaciers—glaciers that rest on the seabed and end with their ice front in the ocean and calve icebergs. The topography beneath these glaciers is often varied; they may sit upon deep canyons, underground mountains, or big flat plains. In Hektoria’s case, the glacier rested on top of an ice plain, a flat area of bedrock below sea level. Researchers previously found that 15,000-19,000 years ago, Antarctic glaciers with ice plains retreated hundreds of meters per day, and this helped the team better understand Hektoria’s rapid retreat.
When tidewater glaciers meet the ocean, they can go afloat, where they float on the ocean’s surface rather than resting on solid ground. The point at which a glacier goes afloat is called the grounding line. Using several types of satellite data, the researchers discovered Hektoria had multiple grounding lines, which can indicate a glacier with ice plain topography underneath.
Hektoria’s ice plain caused a large part of the glacier to go afloat suddenly, causing it to calve quickly. Going afloat exposed it to ocean forces that opened up crevasses from the bottom of the glacier, eventually meeting crevasses exposed from the top, causing the entire glacier to calve and break away.
Tracking the Rapid Retreat
The team used satellite data to study the glacier at different time intervals and created a robust picture of the glacier, its topography, and its retreat.
“If we only had one image every three months, we might not be able to tell you that the glacier lost two and a half kilometers in two days,” Ochwat said. “Combining these different satellites, we can fill in time gaps and confirm how quickly the glacier lost ice.”
The researchers also used seismic instruments to identify a series of glacier earthquakes at Hektoria that occurred simultaneously with the rapid retreat period. The earthquakes confirmed the glacier was grounded on bedrock rather than floating, proving both the presence of an ice plain topography and that the ice loss contributed directly to global sea level rise.
Ice plain topographies have been detected across numerous glaciers in Antarctica, and the research on Hektoria will help scientists anticipate and forecast potential rapid retreat across the continent.
“Hektoria’s retreat is a bit of a shock—this kind of lighting-fast retreat really changes what’s possible for other, larger glaciers on the continent,” Scambos said. “If the same conditions set up in some of the other areas, it could greatly speed up sea level rise from the continent.”
Reference: “Record grounded glacier retreat caused by an ice plain calving process” by Naomi Ochwat, Ted Scambos, Robert S. Anderson, J. Paul Winberry, Adrian Luckman, Etienne Berthier, Maud Bernat and Yulia K. Antropova, 3 November 2025, Nature Geoscience.
DOI: 10.1038/s41561-025-01802-4
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14 Comments
There’s nothing “unusual” about a glacier having a flatbed. The glacier makes the flat bed through erosion. You journalism graduates should have taken a few science courses.
“A glacier on the EASTERN side of Antarctica has undergone the fastest retreat ever documented in modern times.”
Hektoria Glacier is located near the tip of the Antarctic peninsula in what is conventionally called West Antarctica, NOT East Antarctica. The Hektoria Glacier is on the eastern side of the West Antarctica peninsula.
The melting is not surprising because, unlike East Antarctica, the geothermally-active West Antarctica has rapid melting in many areas, even at much higher elevations. Furthermore, according to Google Earth Pro, this relatively small glacier only has an elevation of about 500 feet near the calving front. Therefore, considering the latitude (65 deg south), proximity to the ocean, and potential for anomalous geothermal heat, it isn’t surprising that it is melting.
Furthermore, assuming that the Shutterstock lede photo of an iceberg is of the Hektoria
Glacier bay, it is noticeable to me that there are rhythmic dark bands in the iceberg that look like they are the result not of compression of firn, but instead, re-frozen pooled meltwater, suggesting that this glacier has experienced periodic surface melting. Therefore, one shouldn’t get too excited about a low-elevation, thin glacier setting some kind of Summer calving record when it likely has retreated rapidly, and frequently, in the not too distant past.
You can’t see any of that detail from the Copernicus satellite I’m calling you out! Debate me on the subject. I don’t think you have the testicles for it
I think that the steam coming off your head has fogged your spectacles. I’m more than happy to debate you if you specify what it is that you disagree with. I never mentioned the Copernicus satellite, although it may well have been used for some of the Google Earth imagery, which I did cite for the elevations. I did mention detail in the lede photo from Shutterstock. If that is what you are referring to, then I think that your reply should start with an apology for your rude, inaccurate response. If you want to continue, I’m more than happy to do so if you are willing to behave in a civil manner.
I’m waiting for your apology. It is not good form to falsely accuse someone of behavior that you engage in. It doesn’t do much for your reputation.
Six days and counting.
The air getting hotter, ice is melting, oceans level is rising and the cycle continues. No need to be a scientist to understand that. But maga keep denying the facts.
Why do you feel a compulsion to drag politics into the discussion? I’m one of the more vocal critics here of the global warming paradigm. Yet, I certainly don’t consider myself a MAGA by any means. I offer facts and citations to counter what I consider poorly supported or illogical statements.
Inasmuch as you have demonstrated that you are not a scientist, you are probably unaware that it is commonly accepted that insults and ad hominem attacks, such as “maga,” are a tactic of last resort when those using it have no facts or logical arguments with which to counter. Where are your facts?
I have been to Antartica. For 7 month, during the 2008/2009 Winfly season. Working with the scientists there, from a varied array of fields, not one of them denied climate change was anthropogenic. Now you could say that’s an argument from authority, however, they had no authority over myself in our discussions. I go to the DR when I’m sick. Because they have gone to school for medicine and know more than I. I also go to the scientists when i want science facts. And consenus majority is the realm of science. Could any one or two scientists be incorrect? Obviously. But thousands compared to a few? Doubtful. Is there still a possiblity? Yes. But you could use that argument for literally everything.
Arguing from “authority” has no implication for the number of authorities. In the classic case of determining the age of the Earth, the singular authority, who was very wrong, was Lord Kelvin. But his reputation was such that few dared challenge him, even with facts on their side. Then there were all the physicists who believed that there was such a thing as the “ether,” which served as a medium for the transmission of light. Once widely held, that was wrong also. Then there was all the doctors who believed in blood letting. There are a huge number of ‘scientific’ beliefs that have been discarded because, despite the ‘authority’ of one or many, eventually the number of facts grew too large to ignore and scientists quietly abandoned there former belief systems. It is commonly called a “Paradigm Shift.”
The essence of the Scientific Method is skepticism. It is NOT consensus. The science is never “settled.” If something is decided by consensus, it is not science. Einstein’s Theory of General Relativity was not well received, initially. In fact, 100 physicists signed their names to a book criticizing the theory. Einstein famously responded, “Why 100 when it would only take one to prove me wrong. Even though no one has proven Einstein to have been wrong, a century later, physicists and astronomers keep trying because something cannot logically be proven to be right; it can only be proven to be wrong. That is, the statement that “there is no Bigfoot (or Loch Ness monster, or God)” cannot be proven to be right. It can only be proven to be wrong by capturing a Bigfoot.
indeed, I am obliged to agree with you as to the authority of predominant consensual opinion. One only needs to consider the ridiculous power accorded to the Catholic Church when burnt to death Jan Hus for alleged heresy.
However, there are certain coincidences that have developed in large measure since 1945, after the invention of antibiotics in 1944, that may be taken as indicating that Anthropogenic Global Heating is because of our vastly increased consumption of hydrocarbon energy since then. Or one may take the line that these coincidences are merely normal aberrations.
If they are not, one could even blame antibiotics for global warming as they too have become increasingly numerous since their invention.
Rob, look at Figure 2 here: https://wattsupwiththat.com/2022/03/22/anthropogenic-co2-and-the-expected-results-from-eliminating-it/ for perspective on the contributions of CO2 from humans. Biological contributions and withdrawals (sinks) clearly dominate the Carbon Cycle. The sinks cannot differentiate between natural and anthro’ sources; humans only account for about 4% of the annual flux.
If you would like additional evidence, see Figure 3 here, https://wattsupwiththat.com/2021/06/11/contribution-of-anthropogenic-co2-emissions-to-changes-in-atmospheric-concentrations/ to see how warming impacts the increase of atmospheric CO2 much more strongly than the contributions from Man.
It isn’t surprising that you and others hold the opinions that you do because the media isn’t giving the public the whole story. It is decidedly Cherry Picked to support the AGW meme.
Sorry, but I have a hard time understanding your logic ?
Your statement …
“Working with the scientists there, from a varied array of fields, not one of them denied climate change was anthropogenic…”
I could use an alternate corollary …
” I have lived on this planet for 76+ years and have studied climate science arguments, none of which leads me to believe that CO2 is linked directly to anthropogenic global warming as the major cause of climate change. Backed up by the simple observation, that the Climate has varied extensively (i.e. climate changes) throughout Earth’s 4.54 billion years history, even long before humans ever existed”
Suggest, Instead of using a group of scientists to refer back to, say, see:
” Climate Truths” (Holmes and Godwin,2025), as one of numerous alternate literary references, it states (p43):
“There are zero scientific papers that show empirically from observations based on experiment, that carbon dioxide RAGs cause warming. No one has ever measured this mythical warming of the Earth from IR radiation coming from atmospheric carbon dioxide molecules in an experiment. Let alone attribution from just 4% of carbon dioxide molecules that humans emit. This has never been experimentally shown (Godwin, 2021d).”
Also, your statement …
” And consensus majority is the realm of science. Could any one or two scientists be incorrect? Obviously. But thousands compared to a few? …”
You must know this is not a valid argument?
Particularly when it is obvious that the MSM and ‘AGW pseudo-science groupthink’ does not encourage, and blatantly denies alternate views to be openly discussed and published.
I’ll stop there.
Maybe just another 0.5mm of sea-level rise? More water for fish to swim in……….