The glacier was darker in 2023 due to absence of snow, and the glaciers tongue had retreated.Vital Research at RiskA research group from Switzerland and Italy took cores of ice from Corbassière glacier in 2018 and 2020 to reconstruct past concentrations of the regions aerosols, or tiny airborne particles that were suspended in the atmosphere and then transferred on the ice. Such info from glaciers around the world can supply hints about previous environmental conditions thousands of years ago.Ice cores consist of nitrate, ammonium, and sulfate ions– signatures of aerosols lacing the snow thats deposited on glaciers year after year. Deeper in the ice (and farther back in time), the researchers observed less ions overall and that their quantities varied less than expected.As reported in Nature Geoscience, the group found evidence that previous melting of the glaciers surface between 2018 and 2020 likely penetrated the glacier layers below and carried away the aerosol ions. The valuable info kept in the ice was destroyed.Preserving Our Climate LegacySchwikowski and other ice core specialists from around the world are part of an effort to maintain cores from the last remaining glaciers.
Satellite image of Corbassière glacier in Switzerland captured on August 23, 2001, by Landsat 5. Satellite image of Corbassière glacier in Switzerland captured on August 20, 2023, by Landsat 8. The surface melting of a high-elevation glacier in the Alps has actually rendered it unusable for clinical research.Glaciers are natural archives of past environment. In their frozen layers lies proof of Earths changing temperature and atmospheric structure. As the climate warms, some of the longest records of our altering planet are melting away.The Shrinking Corbassière GlacierOne such archive is the Corbassière glacier in Switzerland. The high-altitude glacier is located on the flanks of Grand Combin, one of the greatest peaks in the western Alps. It has actually suffered the same fate as lots of alpine glaciers in Switzerland, which jointly have lost majority of their volume because the 1930s. A few of the more current modifications at Corbassière glacier are noticeable in these images, recorded in August 2001 (left) and in August 2023 (right). They were acquired by Landsat 5 and Landsat 8, respectively. In simply over twenty years, Corbassière has actually diminished in location and surface area mass. The glacier was darker in 2023 due to absence of snow, and the glaciers tongue had retreated.Vital Research at RiskA research group from Switzerland and Italy took cores of ice from Corbassière glacier in 2018 and 2020 to rebuild past concentrations of the areas aerosols, or tiny airborne particles that were suspended in the atmosphere and then deposited on the ice. Such information from glaciers around the globe can offer clues about previous environmental conditions countless years ago.Ice cores contain sulfate, ammonium, and nitrate ions– signatures of aerosols lacing the snow thats deposited on glaciers every year. Ion concentrations are lower in winter season than in summer due to the fact that less polluted air can increase from the valley when the air is cold.The group analyzed a core drilled from the glacier in 2018 and discovered seasonal changes in the quantity of ion deposits throughout the ice core, as expected.Margit Schwikowski and Theo Jenk. Credit: Riccardo Selvatico”But when we went to core the glacier in 2020, we saw melting on the surface immediately,” said Margit Schwikowski, who is an environmental chemist at Paul Scherrer Institute in Switzerland. Schwikowski led the group of researchers that evaluated the ice cores with PhD trainee Carla Huber. In the 2020 core, seasonal changes of ions were only present in the upper three or 4 annual layers. Deeper in the ice (and further back in time), the researchers noticed less ions total and that their amounts changed less than expected.As reported in Nature Geoscience, the team found proof that previous melting of the glaciers surface in between 2018 and 2020 likely penetrated the glacier layers listed below and carried away the aerosol ions. This melting rendered the core unusable in the teams research, and other attempts to core the glacier had the exact same outcome. The valuable details kept in the ice was destroyed.Preserving Our Climate LegacySchwikowski and other ice core specialists from worldwide are part of an effort to protect cores from the last remaining glaciers. The effort, led by the Ice Memory Foundation, aims to get ice cores from 20 endangered glaciers worldwide in 20 years and collect them in a worldwide environment archive.”Glaciers are retreating worldwide, and we may discover comparable concerns at other sites,” said Schwikowski. Even at the highest elevations in the Alps, she included, “glaciers are on the brink of ending up being unsuitable as natural paleo-archives.”Reference: “High-altitude glacier archives lost due to environment change-related melting” by C. J. Huber, A. Eichler, E. Mattea, S. Brütsch, T. M. Jenk, J. Gabrieli, C. Barbante and M. Schwikowski, 26 January 2024, Nature Geoscience.DOI: 10.1038/ s41561-023-01366-1NASA Earth Observatory images by Wanmei Liang, using Landsat information from the U.S. Geological Survey.