Weak Ice Arches Allowing Sea Ice to Leave Arctic
02.03.2010 - Water & Oceans, Ice & Snow, Arctic
Large chunks of ice that clump together to form ice arches spanning the straits that lead out of the Arctic Ocean usually prevent the ice from moving around and fleeing the ocean. In recent years, however, these ice arches have been failing to form. The consequences of the resulting sea ice migration into the Atlantic and Pacific Ocean on ocean circulation and marine life could be disastrous.
A team of researchers from the Jet Propulsion Laboratory in Pasadena, California, has studied satellite images of the Nares Strait, the narrow passage between Greenland and Ellesmere Island in Canada. They noted when the arches formed in the last 13 years as well as the amount of ice that was allowed to flow down the strait. The researchers believe that higher temperatures are to blame. As global temperatures have warmed, Arctic ice thins out and eventually becomes too weak to build the arches.
Although this year is again marked by the absence of arches in the strait, the researchers remark that ice arches are plugging up many other openings in the Arctic, including the Bering Strait and parts of the Canadian archipelago. They suspect, however, that should these arches fail too, heavy ice traffic leaving the Arctic would lower the salinity of the water and affect ocean circulation, not to mention disrupt ecosystems that are adapted to ice-free conditions.
