NASA ICESat-2 Space Lasers Predicts Chronic Melting, Maps Meltwater Lakes in Antarctica

Antarctica's ice sheet is evidently thick and has a massive size. However, the ice sheets and caps that cover the southern pole of the planet can move instantly. The Antarctic sheet can reform itself by rising, collapsing, and expanding in just a few hours. There are many factors that affect these transitions, and one of them is meltwaters. Using an advanced satellite, NASA maps these meltwaters to understand the Antarctic waterways better.

NASA Space Lasers Maps Surface Changes in Amery Ice Shelf, Antarctica Meltwater Lakes Funnel Freshwater to Southern Oceans

NASA's Ice, Cloud, and Land Elevation Satellite 2, also known as ICESat-2, was the satellite used for mapping the meltwater lakes on the Antarctic ice sheet. ICESat-2 can map the ice sheets on the continent regardless of their thickness. According to NASA Earth Observatory, The satellite can detect even the tiny changes in the Antarctic surface due to meltwater lakes accurately, scaling down to centimeters.

ICESat-2 is an instrument valuable for tracking the process change in the Antarctic ice sheet, said Scripps Institution of Oceanography's glaciologist Helen Amanda Fricker. The transitions that the southern continent's ice caps undergo are huge, and these sheets can reform in just a few hours. Fricker said that the movements, even massive, cannot be detected and predicted easily before. Fortunately, ICESat-2 functions very well for the research about Antarctica's future.

Antarctic's chronic melting is the cause of reformation in the vast surface of the ice sheets. In a study recently published in the journal Geophysical Research Letters entitled "Rapid formation of an ice doline on Amery Ice Shelf, East Antarctica," ICESat-2, together with Landsat 8, have obtained enough data to determine the sequence of the instant change in the ice shelves. The changes produced ice-covered meltwaters, and most of them are found at the Amery Ice Shelf, the Antarctic's third-largest ice shelf.

Antarctic Dolines in Winter, Freshwater, and Oceanic Ecosystem

Glaciology experts have observed a huge volume of water draining to the ocean body below the ice shelf due to the fracture on the surface of the chunk. This movement imprinted a crater-like formation on the surface, also known as doline, that spans an area of 10 square kilometers. Fricker, along with her fellow glaciologists, has recorded freshwater being funneled to East Antarctica with a volume of almost 200 billion gallons.

Antarctica's ice sheets exhibit dotted features, mostly due to meltwaters, during summer. However, the massive chronic melting displayed in the study occurred during the winter. The water on Antarctica's ice shelves was supposed to be frozen at the time, reports UC San Diego.

Using the Advanced Topographic Laser Altimeter System ATLAS aboard the ICESat-2, the researchers have successfully mapped the changes in the Amery Ice Shelf. ATLAS is equipped with a photon-counting lidar system that functions through laser light pulses projected by the satellite to the Earth's surface and back to the sensor. Through the photons, researchers read the precise rise and drop on the sheet along with the meltwater lake transitions. With the help of Landsat 8's Operational Land Imager, a clear image of the physical changes in the ice sheet's structure was also captured.

Doline formation observed at the Antarctic's ice sheet is challenging to capture, and having the opportunity to observe the rare event allowed the experts to understand the ice dynamics better than before. The findings are necessary to determine the hidden plumbing system that causes massive ice slips throughout the oceans in the southern hemisphere. Further studies using the ICESat-2 will help us identify the influences of the meltwater lake's overflowing fresh water on the circulation and ecosystem of our planet's oceans, reports Eurasia Review.

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