The imprint of climate change on modern glaciers Silvia Ferrer 01/09/2024 08:41 6 min
Research reveals that The glaciers of the Andes are currently experiencing an unprecedented retreat. Today, ice zones have been exposed that have not been seen for 11,700 years, that is, since the beginning of the Holocene.
The study led by scientists at Boston College (United States) and recently published in the journal Science, not only shows this decline, but also the increase in the rate at which these glaciers are melting. Showing very significant evidence of the impacts that climate changes are causing on ice masses.
The world’s glaciers are melting much faster than expected.
Precisely, the Andes are home to almost 100% of tropical glaciers, which due to global warming in this area of the planet, They are the first to show the impacts of anthropogenic climate change on a regional scale.
How do rocks give us information?
There are two rare isotopes that accumulate on the surface of bedrock when it is exposed to cosmic radiation. which comes from outer space, that is, when the rock is found in the open air.
The two isotopes resulting from cosmic radiation are beryllium-10 (10Be) and carbon-14 (14C). Beryllium-10 is a radioactive isotope of beryllium formed mainly by the spallation of cosmic rays of oxygen. And carbon-14 or radiocarbon is a radioactive isotope of carbon with a nucleus of 6 protons and 8 neutrons, which decays producing beta radiation, with a half-life of 5,730 years. 14C is used for dating, being applicable to organic materials and some inorganic materialsbut not to metals.
The team of scientists from Boston College traveled to Colombia, Peru and Bolivia to carry out measurements of these two radioactive isotopes. in the bedrock that has only recently been exposed in front of four of the melting glaciers in the Andes.
Chile, Argentina
Spectacular views of Patagonia with Mount Fitz Roy in the background
Cerro Chalten or Mount Fitz Roy is the highest mountain in Los Glaciares National Park in Patagonia (Andes, border of Chile and Argentina). The summit of Fitz Roy is surrounded on all pic.twitter.com/bE6icFrnen
— ? Ali Al Samahi ? (@alsamahi) August 28, 2024
This team has been applying the same technique to glaciers along the American Cordillera, from Alaska to Tierra del Fuego.and plans to combine the results to obtain a global perspective on the current state of global glacier retreat.
What is the relationship of the results obtained?
Scientists after analyzing rock samples adjacent to four glaciers in the Andes, were able to determine how long ago these rocks had been previously exposed, as well as the fact that glaciers were often smaller than they are today.
In the measurements obtained, it was observed that Most of the samples analyzed had concentrations of the radioactive isotopes 10Be and 14C close to zero. This result suggests that these rocks were covered by ice throughout the Holocene period until now. Therefore, The glaciers adjacent to these rocks are now probably smaller than they have been at any time in the last 11,700 years of the Holocene.
These results are a dramatic reminder of the perilous state of glaciers in our warming world.
Scientists had already predicted that glaciers would melt or retreat as temperatures rose in the tropics. Rising temperatures are therefore the main cause of their decline, and The study’s findings indicate that more of the world’s glaciers are likely retreating, possibly decades earlier than anticipated.
The report concludes that The tropics have already warmed above the maximum range reached in the early Holocene. And it suggests that we have already entered the Anthropocene, due to the significant global impact that human activities are having on terrestrial ecosystems.
Reference
Andrew L. Gorin, et al (2024) “Recent tropical Andean glacier retreat is unprecedented in the Holocene” Science DOI: 10.1126/science.adg7546
