Oregon State University research has discovered a potential explanation for the rapid retreat of glaciers that terminate at the sea: the release of small, pressurized bubbles in underwater ice.
Published in Nature Geoscience, the study reveals that glacier ice, which contains pockets of pressurized air, melts much faster than bubble-free sea ice or artificial ice typically used to study melt rates at the ocean-ice interface of tidewater glaciers.
The authors state that tidewater glaciers are retreating rapidly, leading to ice mass loss in Greenland, the Antarctic Peninsula, and other glacierized regions worldwide.
“We have been aware for some time that glacier ice contains bubbles,” said Meagan Wengrove, assistant professor of coastal engineering in the OSU College of Engineering and the study’s leader. “However, it was only when we began discussing the physics of the process that we realized these bubbles may have a much larger role than simply creating noise underwater as the ice melts.”
Glacier ice forms through the compression of snow. Air pockets between snowflakes become trapped in pores between ice crystals as the ice moves from the surface layer of a glacier to its interior. There are approximately 200 bubbles per cubic centimeter, meaning that glacier ice consists of about 10% air.
2023-09-07 10:48:02
Original from phys.org