Geophys. Res. Lett. doi:10.1029/2008GL034271 (2008)

The contents of a sediment trap suspended more than 3,000 metres below the sea surface may force a reassessment of the Arctic Ocean's carbon cycle.

Jeomshik Hwang and his colleagues from Woods Hole Oceanographic Institution in Massachusetts report that organic carbon caught in their sediment trap in the Canada Basin is “strikingly old”, with an approximate age of 2,000 years. If the carbon in the trap came from particulate matter descending from the surface, as oceanographers would expect, its age should be indistinguishable from that of surface carbon.

The findings imply that organic carbon at a depth of 3,000 metres largely originates from the basin's surrounding margins. This sets the Canada Basin apart from other ocean basins studied and means that models generally used to describe ocean carbon cycling do not apply in the Arctic.