Research Highlights

Nature 455, 711 (9 October 2008) | doi:10.1038/455711a; Published online 8 October 2008

Geosciences: The melting ocean

Nature Geosci. doi:10.1038/ngeo316 (2008)

After 1997, a glacier that drains 7% of Greenland's ice sheet switched from thickening slowly to thinning quickly, causing the glacier's velocity to double. Several theories have been put forward to explain the change, including increased lubrication of the bedrock beneath the glacier. David Holland of New York University and his team conclude that it was induced by a sudden rise in the subsurface ocean temperature along Greenland's west coast.

They studied data from laser-altimeter surveys carried out by aircraft along 120 kilometres of the Jakobshavn glacier, and oceanographic observations recorded around the nearby port of Ilulissat. The pulse of warm water that arrived in 1997 came from the Irminger Sea near Iceland, they report, entering the subpolar gyre off Greenland after the North Atlantic Oscillation weakened during the winter of 1995–96.