MOISTURE SUPPLY FOR NORTHERN ICE-SHEET GROWTH DURING THE LAST-GLACIAL-MAXIMUM

During the last ice age, the Barents Sea ice sheet began to grow 22 ky r ago(1), only 8 kyr before it began to disintegrate(2). This implies that the ice must have grown very rapidly from the coast to the edge o f the continental shelf. Such rapid growth of a large ice sheet requir es significant amounts of moisture; but the origin of this moisture ha s been unclear, particularly as the CLIMAP climate reconstruction sugg ests(4,5) that the Greenland-Iceland-Norwegian (GIN) seas were perenni ally ice-covered during this period. Here we present data from deep-se a sediment cores from the Fram Strait, which suggest that relatively w arm water from the North Atlantic Ocean was advected into the GIN seas in two short-term events (27-22.5 and 19.5-14.5 kyr ago). We suggest that the resulting seasonally ice-free waters were an important region al moisture source for the Barents Sea ice sheet, and that the GIN sea s played a much more active role in climate during the last glaciation than has previously been supposed.