A study by the space agency's Jet Propulsion Laboratory in Pasadena, Calif., the University of California-Irvine and the University of British Columbia involved measuring the undersea melting rates of four glaciers during the summer of 2008.
The scientists said their findings suggest undersea melting caused by warmer ocean waters is playing an important, if not dominant, role in the current evolution of Greenland's glaciers -- a factor that had previously been overlooked.
Scientists Eric Rignot, Isabella Velicogna and Michele Koppes said they used oceanographic equipment in the glacier fjords, sampling the water at various depths to measure ocean currents, temperature and salinity, along with the depth of the fjords.
Rignot said the new study complements other research on the effects of ocean conditions in Greenland fjords.
"Our study fills the gap by actually looking at these submarine melt rates, something that had never been done before in Greenland," Rignot said. "The results indicate rather large values that have vast implications for the evolution of the glaciers if ocean waters within these fjords continue to warm."
The findings are reported in the early online edition of the journal Nature Geoscience.