{"id":939315,"date":"2026-05-05T12:41:45","date_gmt":"2026-05-05T12:41:45","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/939315\/"},"modified":"2026-05-05T12:41:45","modified_gmt":"2026-05-05T12:41:45","slug":"record-setting-retreat-of-hektoria-glacier","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/939315\/","title":{"rendered":"Record-Setting Retreat of Hektoria Glacier"},"content":{"rendered":"

To say something moves at a glacial pace is to imply sluggish, unhurried change. But what transpired over the course of 15 months at Antarctica\u2019s Hektoria Glacier was uncharacteristically quick. Between January 2022 and March 2023, the glacier lost about 25 kilometers (15 miles) in length. That included a two-month period in which the terminus<\/a> retreated more than 8 kilometers (5 miles)\u2014the highest rate of grounded glacial ice loss observed in modern history.<\/p>\n

A team of scientists published an analysis of Hektoria\u2019s collapse<\/a> based on a suite of remote-sensing data, finding that its particular geometry enabled the rapid change. Like many glaciers on the Antarctic Peninsula, Hektoria starts on land and extends to the sea, with the last section being a thick, floating plate of ice, or \u201cice tongue.\u201d The researchers determined Hektoria lost both its ice tongue and an area of grounded ice spread over a flat plain\u2014the latter directly contributing to sea level rise. Although Hektoria is relatively small as Antarctic glaciers go, scientists say that similar events at larger glaciers could be much more consequential.<\/p>\n

The images above capture the scale of the loss of Hektoria\u2019s grounded ice on the eastern Antarctic Peninsula. Note that the right image was acquired about one year after the remarkable loss of grounded ice; a cloud-free Landsat image showing the whole area was not available from the previous March. Hektoria\u2019s terminus remained relatively stable after the sudden loss, the study reported, though the neighboring Green Glacier continued to retreat.<\/p>\n

The chain of events culminating in Hektoria\u2019s breakup goes back to early 2002. At that time, the Larsen B ice shelf, which served as a backstop for Hektoria and neighboring glaciers, splintered and collapsed<\/a> in short order. The glaciers then thinned<\/a> and retreated for several years. In 2011, landfast sea ice<\/a> in the Larsen B embayment near Hektoria\u2019s terminus filled in enough to allow the glacier to start advancing.<\/p>\n

But after several years, the new support for the glacier front was suddenly removed. Landfast ice in the embayment broke up<\/a> in January 2022, likely due to large, destabilizing ocean swells<\/a>. From that point, rapid change at Hektoria was again underway. Throughout the rest of the austral summer, the floating ice tongue disaggregated in a series of calvings, resulting in a loss of 16 kilometers.<\/p>\n

The glacier\u2019s terminus stabilized during the 2022 austral winter. However, satellite-based laser altimetry data, including ice elevation measurements from NASA\u2019s ICESat-2<\/a>\u00a0(Ice, Cloud, and Land Elevation Satellite-2) mission, revealed that the ice continued to thin<\/a> during that winter.<\/p>\n

The thinner remaining ice was still grounded during the 2022 austral spring (left image, above), the study authors concluded, based on the detection of earthquakes occurring beneath the glacier. They determined the ice was spread out over a relatively flat area of bedrock, forming an ice plain. This geometry allows seawater to infiltrate the glacier\u2019s bed during high tide and intermittently lift ice off the ground. When ice is thin enough, large areas can lift and break away at once. The process, called buoyancy-driven calving, is believed to have caused the second stage of Hektoria\u2019s rapid retreat, resulting in an additional loss of 8 kilometers in length.<\/p>\n

Naomi Ochwat, a glaciologist at the University of Innsbruck and the study\u2019s lead author, is now looking into other glaciers that may be at risk of destabilizing in a similar way. As the Antarctic Peninsula responds to warming, more of its glaciers are losing their ice tongues, and their termini are now resting on the seabed, as Hektoria’s does. (Called tidewater glaciers<\/a>, this type is common in Alaska and Greenland.) New technologies developed by NASA and partners can aid in understanding rapid glacial retreat, said Ochwat and study co-author Ted Scambos, a senior research scientist at the University of Colorado Boulder.\u00a0<\/p>\n

The\u00a0NISAR<\/a>\u00a0(NASA-ISRO Synthetic Aperture Radar) satellite, for example, can detect the movement of land and ice surfaces down to the centimeter. Its data will be \u201cvery useful for structural evaluations of Hektoria and other glaciers in the region,\u201d Scambos said.<\/p>\n

\u201cIn addition to NISAR,\u201d Ochwat added, \u201cI’m particularly interested in learning what SWOT can tell us about rapid glacier changes.\u201d The\u00a0SWOT<\/a>\u00a0(Surface Water and Ocean Topography) satellite\u2019s primary mission is to observe the fine details of Earth\u2019s surface water height. But scientists are also exploring its applications to the cryosphere, such as measuring surfaces of ice shelves<\/a> and sea ice<\/a>.<\/p>\n

At Hektoria Glacier, the days of dramatic change are likely past, now to be replaced by slow retreat. Scambos said he would not be surprised to see the ice slowing down. \u201cThe glacier has lost so much elevation and mass that it simply can\u2019t continue to maintain the same output,\u201d he said. \u201cIt\u2019s on its way to being a fjord<\/a>, not a glacier.\u201d<\/p>\n

NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the\u00a0U.S. Geological Survey<\/a>. Story by Lindsey Doermann.<\/p>\n

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