Valais glaciers have become useless as a climate archive
Published: Friday, Jan 26th 2024, 13:00
العودة إلى البث المباشر
In Switzerland, an important source of information on climate and air pollution has been lost due to glacier melting. The Corbassière glacier on the Grand Combin in Valais is melting faster than previously assumed and therefore no longer provides reliable data.
This is the conclusion of a study by scientists from Switzerland and Italy, which was published in the journal "Nature Geoscience". The research paper was written by a team led by Margit Schwikowski, Head of the Environmental Chemistry Laboratory at the Paul Scherrer Institute (PSI) in Villigen AG, and Carla Huber, PhD student and first author of the study.
The PSI scientists, together with colleagues from the University of Freiburg and the University Ca' Foscari in Venice and the Institute of Polar Sciences of the Italian National Research Council, analyzed ice cores that had been drilled into the Corbassière Glacier in 2018 and 2020.
Glaciers are invaluable for climate research, according to a press release issued by the PSI on Friday. The climate and atmospheric conditions of past eras are preserved in their ice. Similar to tree rings or marine sediments, they can serve as a so-called climate archive for research.
The amount of trace elements in the ice normally fluctuates with the seasons. These substances, such as ammonium, nitrate and sulphate, originate from the ambient air and are deposited on the glacier by snowfall. The concentration is high in summer and low in winter because the cold prevents the polluted air from rising from the lowlands.
The ice core from 2018 showed the expected fluctuations and contained deposits dating back to 2011. The 2020 core, on the other hand, only showed these fluctuations in the upper three to four annual layers. Further down in the ice and thus further back in time, the curve becomes flatter and the total amount is lower.
According to Schwikowski, the glacier melt between 2018 and 2020 must have been so strong that water often and in large quantities reached the inside of the glacier from the surface and carried the trace elements it contained with it. "But apparently, once the water was there, it didn't freeze again and concentrated the trace elements. It flowed away and literally leached them out," concludes the researcher.
©كيستون/إسدا
Arabic 
English 
German 
French 
Spanish