Beijing, February 8 (Xinhua) -- A research report published in the British monthly journal Nature Earth Science on the 7th showed that with the advancement of satellite technology, scientists have been able to accurately estimate the ice content of global glaciers, and the latest valuation is about 20% less than the previous valuation. Among them, the ice content of mountain glaciers is quite different from the previous estimates.
This imposition image shows a complete view of Fox Glacier in New Zealand in 2012 (left) and Fox Glacier (right) taken aerialally on April 19, 2021. (Photo by Xinhua reporter Guo Lei)
Glaciers are important freshwater resources on the surface of the earth, mainly distributed in the earth's poles and high mountainous areas at medium and low latitudes, the former belongs to continental glaciers, also known as ice sheet glaciers, and the latter belongs to mountain glaciers. Glacier ice content depends mainly on the size of the glacier and the distribution of ice thickness. Researchers can extrapolate the distribution of ice thickness based on glacier movement, but for many years, due to technical limitations, collecting relevant data has been more challenging.
In the study, led by Roman Milan, a postdoctoral fellow at the French Institute of Environmental and Earth Sciences, researchers used high-resolution satellites deployed in space in recent years to study for the first time how 98% of the world's glaciers move on the surface, thus accurately estimating the distribution of ice thickness and estimating the ice content of glaciers.
On March 20, 2019, at the Aletsch Glacier under the Jungfraujoch, Switzerland, a young Swiss man displays a postcard calling for a fight against climate change. (Photo by Xu Jinquan, Xinhua News Agency)
The researchers analyzed more than 800,000 satellite images of glaciers taken from 2017 to 2018 and found that many of them were not as thick as previously estimated. According to the latest estimates, if global glaciers melt, it could cause sea levels to rise by an average of about 26 centimeters, which is about 7 centimeters less than previously estimated.
Based on the study, previous studies overcalculated the number of glaciers at the edge of the Greenland ice sheet and the Antarctic ice sheet, thereby overestimating the ice content of the ice sheet glaciers. Glacier ice content also differs significantly from previous estimates in high-altitude mountainous areas at mid- and low-latitude latitudes, for example, the Northern Hemisphere Himalayas have 37 percent more glacial ice than previous estimates, while the Andes in South America contain 27 percent less ice than previous estimates.
The researchers say that understanding glacier motion and ice thickness refreshes the academic community's understanding of the distribution of ice mass around the world, helping to predict the evolution of glaciers around the world. (Wang Xinfang)