Ocean ice sheets shattered by big waves

Recently, the news -- much of it dire -- has been filled with stories, studies and predictions of melting ice. Now, there's more: waves, not warming, do much of the work in breaking up ice sheets and accelerating melting. That according to new research out of New Zealand.
A new study, published in Nature this week, has shown that waves reverberate across ice sheets much more than previously thought, working to break up the ice and hastening the transition from ice sheet to ice flow -- and eventually to ice-no-more.
Ice sheets are different from ice shelves, the giant masses of ice that mostly occupy polar land while slowly slipping into the ocean. Sheets on the other hand are the sizable portions of ice that form on top of the ocean surface and surround the polar regions' land masses.
And sheets, which occupy some 10 million square miles of Earth's surface, aren't so much affected by a warming climate as they are by large waves.
According to the new research conducted by Dr. Alison Kohou and her fellow scientists at the National Institute of Water and Atmosphere Research (NIWA) in New Zealand, waves of three meters (about ten feet) or higher can have significant impact on sea ice sheets -- reverberating across the sheet for up to 220 miles.
Sea ice, Kohou and her colleagues say, is just as important as the ice shelves in terms of their role in regulating climate.
Ice sheets, for example, reflect the the sun's rays, thus shielding Earth from solar heat. Ice sheets also insulate the ocean water below, helping moderate ocean temperatures and control weather patterns.
But more research needs to be done to understand the behavior of ice sheets. Luckily, researcher Dr. Mike Williams thinks we now have the capability to learn more.
"When the experiments required for this research were last carried out in the 1970s and 1980s, people needed to be sitting on the sea ice to take measurements and that meant they couldn't be out there when the big waves came through," Dr. Williams said. "Now we have autonomous equipment that can be out there during storms and that's what gave us the ability to get the new data."
And although warming is a huge factor in determining the size or behavior of ice sheets, scientists think climate change could encourage bigger ocean storms -- storms which could produce bigger waves, chipping away at the poles' blanket of ice.