The Japanese icebreaker ship Shirase is pictured in Lützow-Holm Bay, near Shirase Glacier, during the 58th Japanese Antarctic Research Expedition, which was conducted in 2017. Photo by Kazuya Ono
Aug. 24 (UPI) -- Scientists have discovered a new melting hotspot in East Antarctica, home to most of the Antarctic ice sheet, Earth's largest freshwater reservoir.
According to a new study, published Monday in the journal Nature Communications, an influx of warm seawater into the Lützow-Holm Bay has accelerated melt rates beneath the Shirase Glacier Tongue.
The sub-glacier melting hotspot was identified by a team of Hokkaido University scientists during the 58th Japanese Antarctic Research Expedition. The icebreaker ship was able to make its way into Lützow-Holm Bay after a serendipitous breakup of heavy sea ice.
"Our data suggests that the ice directly beneath the Shirase Glacier Tongue is melting at a rate of 7 to 16 meters per year," study co-author Daisuke Hirano, said in a news release.
"This is equal to or perhaps even surpasses the melting rate underneath the Totten Ice Shelf, which was thought to be experiencing the highest melting rate in East Antarctica, at a rate of 10 to 11 meters per year," said Hirano, an assistant professor of oceanography at Hokkaido University's Institute of Low Temperature Science.
Understanding the relationship between climate change and melting in Antarctica is essential to predicting sea level rise. On average, models suggest seas are likely to rise a little more than 3 feet by the end of the century, but the range of predictions is rather wide.
Even if humans are able to reduce carbon emissions and curb carbon emissions, some studies have suggested that Antarctica's glaciers are likely to continue melting at an accelerated clip long after a slowdown in global warming.
Most efforts to improve Antarctic melting models have focused on West Antarctica. Until now, scientists thought ocean currents mostly brought cold water to the Antarctica's east coast.
Over the course of the 2017 expedition to East Antarctica and the Shirase Glacier Tongue, Hokkaido researchers recorded data on water temperature, salinity and oxygen levels at 31 different locations. Scientists combined their measurements with data on the area's currents and wind, as well as ice radar measurements.
When researchers fed their data into a model designed to simulate coastal ocean currents near the inland base of Shirase Glacier Tongue, the simulations revealed the melting effects an ongoing influx of deep, warm water.
Simulations showed the warm water moves through a deep ocean trough and melts the base of Shirase Glacier Tongue. As the warm water rises up and away from the base, it mixes with the glacial meltwater.
Though the latest research suggests the melting occurs year round, simulations suggest that when the region's typically strong easterly, alongshore winds weaken during the summer months, the influx of the deep warm water increases, accelerating melt rates.
"We plan to incorporate this and future data into our computer models, which will help us develop more accurate predictions of sea level fluctuations and climate change," said Hirano.