Frontal ice ablation in northern hemisphere glaciers

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A recently published article in Nature Communication estimates that during the decade 2010 to 2020, each year, on average, about 52 billion tons of glacial ice were thrown into the sea by frontal ablation of about 1,500 glaciers in the northern hemisphere (at the exclusion of the northern hemisphere ice sheet). Greenland).

These investigations suggest that this process of frontal ablation may have in some regions an even greater weight than that of melting at the glacier surface and has implications for estimates of sea level rise and identification. “hot spots” in which this process takes place.

glaciers

Glaciers lose mass through different processes. Frontal ablation refers to those by which glaciers shed ice directly into the ocean. Its two main components are iceberg calving and submarine melting on glacial fronts, which are independent of surface melting. Previous studies have calculated some of these components in certain regions, but the recently published study is the first to estimate frontal ablation from hemispheric-scale observations.

To estimate the role of frontal ablation from 2000 to 2020, William Kochtitzky (University of Ottawa) coordinated a scientific study with 18 researchers from thirteen European and North American universities, including Francisco Navarro, professor at the Polytechnic University of Madrid, which identified about 1,500 sea-terminating Northern Hemisphere glaciers, excluding those directly offloading the Greenland Ice Sheet (for which separate estimates are available).

They combined measurements or estimates of the thickness and velocity of ice on glacial fronts and changes in their terminal position, concluding that frontal ablation may be the main contributor to glacier mass loss in some regions.

glacial dump

The authors suggest that the glacial outflow during the period 2000-2020 is equivalent to 2.1 mm of sea level rise. Glacial discharge combines frontal ablation with the retreat or advancement of the position of the fronts glaciers.

The share corresponding to frontal ablation was 44,000 million tonnes per year during the period 2000-2010. It was 52,000 million tons per year between 2010 and 2020. They also identified the areas most affected by this process. They found potential hotspots and impacts on marine ecosystems. It also allowed them to determine that the most affected coastal areas are the Russian Arctic, Svalbard and Alaska.

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Reference article: https://www.upm.es/?id=dd8cead4d95d3810VgnVCM10000009c7648a____&prefmt=articulo&fmt=detail

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