Deleterious climate change is bound to spell trouble for communities living near coastlines, as rising global temperatures are bound to accelerate the loss of surface ice around our planet, contributing even further to our rising sea levels. And now, new research published in the journal The Cryosphere has recently revealed that the waters that run off some of our land-based ice fixtures may be accelerating this melting even further.
The melting of glaciers causes these giant frigid structures to “flow,” revealing terrain that up until recently has been locked beneath meters of ice as it creeps down from higher terrain. The meltwater created by this glacial retreat can sometimes pool in the crevasses at the foot of the glacier, forming glacial lakes. However, much like how glaciers that end in the sea possess accelerated melting, those that end in these glacial lakes are also exposed to twice as fast an ice flow rate, leading to double the melting rate.
This alarming conclusion was the product of the work of a team of scientists together with The University of St. Andrews researcher and lead investigator Tobias Bolch, and was found by analyzing over 300 glaciers whose surface area is greater than 3 km2 within the Himalayan region. Of these 300, some 60 of them possess a glacial lake, which feeds nearby rivers such as the Ganges and Brahmaputra.
Bolch and team enlisted the help of the European Space Agency’s (ESA’s) Sentinel-2 satellites. These satellites gathered infrared images of the designated area; the team then employed the help of an algorithm to identify debris that can be found on the surface of the ice and noted down how the debris moved down the valleys left behind by the retreating glacier over time.
It’s through the help of the satellites where Bolch and the team noticed a startling observation: the glaciers that terminated on lakes moved at about 20 m per year, compared to the 10 m per year exhibited by those that ended on land—the lake-terminating glaciers flowed twice as fast.
“These findings are very important for forecasting the availability of water,” said Bolch in a statement. Lead author Jan Bouke Pronk also added that “we have only now analyzed this phenomenon on a large scale and in detail for mountain glaciers.”
Bolch continued: “[Until] now, the accelerating effect of glacial lakes has not been taken into account in predictions. So water shortages in the affected regions in Asia could occur sooner than expected;” here, Bolch is referring to the accelerated loss of glacier ice also accelerating the exhaustion rate of freshwater supplying the Himalayas’ major rivers, whose waters are used by hundreds of millions of people as it courses through the continent.
References
- AFP. (2022, January 27). Glacier lakes make permanent ice disappear over twice as fast, study reveals. ScienceAlert. https://www.sciencealert.com/study-says-glacier-lakes-are-accelerating-disappearance-of-permanent-ice
- Glacial lakes accelerate the disappearance of permanent ice. (2022, January 27). Swiss National Science Foundation. https://www.snf.ch/en/qlNCBCJ6KEBWj7A5/news/
- Pronk, J. B., Bolch, T., King, O., Wouters, B., & Benn, D. I. (2021). Contrasting surface velocities between lake- and land-terminating glaciers in the Himalayan region. The Cryosphere, 15(12), 5577–5599. https://doi.org/10.5194/tc-15-5577-2021
