Arctic Ice Shelf Theory Challenged by Ancient Algae

Arctic Ice Shelf Theory Challenged by Ancient Algae

For more than 50 years, scientists have debated whether a massive ice shelf—up to 1 kilometer thick—covered the entire Arctic Ocean during past ice ages, transforming the frigid water into a solid icy surface similar to Antarctica’s Ross Ice Shelf. The hypothesis dates to the 1970s, when British glaciologist John Mercer and others proposed that during extremely cold periods, continental ice sheets would have extended far into the Arctic Ocean. I…