A group of American scientists studied ocean waters near the 30-kilometer Lecomte Glacier in Alaska. It turned out that the rate of its melting exceeds the previously calculated indicators. Scientists reported their work in the journal Geophysical Research Letters.
This work is a continuation of a study in which scientists measured the rate of melting of a glacier by directing sonar from a ship. Scientists found the ice melting rate much faster than expected, but could not explain why. In the new work, researchers from Rutgers University, Alaska and Oregon Universities decided to understand the driving force behind these processes using unmanned kayaks.
It turned out that the melting process is strongly associated with underwater currents and water flowing to the glacier. It turned out that there are two types of melting occurring near glaciers. Where fresh water flows to the base of the glacier from the surface zone, its powerful flows lead to the melting of the ice. Another option is that the lower part of the glacier can melt under the influence of the water flowing to it. The researchers found that the rate of such melting is significantly - 100 times - higher, as well as the share in the total volume of melt water.
Prior to the study, scientists had few direct measurements of the rate of melting of glaciers through tide and had to rely on untested theory to estimate and model ocean-glacier interactions.
Research findings challenge these theories. The new work is a step towards a better understanding of underwater melting, a process that should be better represented in the next generation of models estimating sea level rise and its consequences.