Greenland's fastest-moving glacier has gained the highest flow speed ever observed in any sea-bound glacier in Greenland or Antarctica.

Credit: Konrad Steffen/Cires/University of Colorado/Amap

Jakobshavn Isbræ (pictured) in West Greenland has been retreating since the mid-1990s. Using high-resolution satellite radar observations to map the glacier's movements since 2009, Ian Joughin at the University of Washington in Seattle and his colleagues report that it has sped up by 30–50% in the past two years. In the summer of 2012, the glacier reached a record pace of more than 17 kilometres per year — four times greater than during the 1990s.

The Cryosphere 8, 209–214 (2014)