New Arctic Survey Reveals Sharp Decline in Old, Thick Sea Ice

A four month sea-ice survey conducted across the central Arctic Ocean this summer has revealed a steep decline in thick, multi-year sea ice, with large areas once composed of thicker ice floes now covered with thin layers of new ice. In other areas, such as the Laptev Sea, where scientists encountered newly formed ice as recently as four years ago, the seas are now ice-free. Using a sophisticated new instrument called the “EM Bird” — a four-meter-long, helicopter-mounted probe capable of measuring ice thickness through electromagnetic induction — a team of scientists from the Alfred Wegener Institute for Polar and Marine Research was able to create an ice thickness profile covering more than 2,500 miles. In many instances, they found areas once covered with two- to five-meter-thick floes now contain one-year-old ice just 90 centimeters thick. While some regions, including the Canadian Basin and an island group in northern Siberia, still contain large amounts of older ice, most other areas have experienced significant ice loss. Overall, the scientists found that sea ice extent was similar to 2007, when sea ice diminished to a record 4.3 million square kilometers.