Underwater glaciers melting faster

NEW YORK: Underwater melting of tidewater glaciers is occurring much faster than was predicted, said researchers. They used a new approach to directly measure submarine melt, which could enhance projections of sea level changes.
The findings published in the journal Science could lead to improved forecasting of climate-driven sea level rise, based on a new method developed by the researchers.
“Tidewater glaciers around the globe — in Greenland, Alaska, Antarctica and beyond — are retreating and raising sea levels globally, submarine melting has been implicated as a trigger for this glacier retreat, but we have had no direct measurements of melting, let alone how it might vary in time,” said study co-author Rebecca Jackson from Rutgers University in the US.
“Our study shows that the prevailing theory significantly underestimates melt rates. These results suggest a stronger coupling between the ocean and glacier than previously expected and our work provides a path forward to improve our understanding of how the ocean impacts glaciers,” Jackson said.
For the findings, the researchers studied the underwater melting of the LeConte Glacier, a tidewater glacier in Alaska, from 2016-2018.
The research team used sonar to scan the glacier’s underwater face; downstream measurements of currents, temperature and salinity to estimate the meltwater flow; radar to measure the glacier’s speed above water; time-lapse photography to detect iceberg calving; and weather station data to measure the surface melt from the glacier.
They found that melt rates are significantly higher than expected across the whole underwater face of the glacier. — IANS