Oceandrilling Research Unveils Arctic Ocean History
21.06.2007 - Logistics, Other
The history of the Arctic ocean during the Cenozoic era (0-65 milion years ago) is largely unknown from direct evidence. Through analysis of a 428 meters sediment core extracted from the Lomonosov ridge in 2004, scientists from the Integrated Ocean Drilling Program's Arctic Coring Expedition (ACEX) were able to peer into the palaeoenvironmental history of the Arctic Ocean.
In the June 21 issue of Nature Magazine, ACEX researchers report that the Arctic Ocean changed from a landlocked body of water (a "lake stage") through a poorly oxygenated "estuarine sea" phase to a fully oxygenated ocean some 17.5 million years ago. They attribute the change in Arctic conditions to the evolution of the Fram Strait into a wider, deeper passageway that allowed an inflow of saline North Atlantic water into the Arctic Ocean.
These results shed light on the history of the circulation regime in the North Atlantic and Arctic Oceans, which are key drivers of the global thermohaline circulation and hence also of global climate. Co-chief scientist Jan Backman, Stockholm University, comments on the significance of the new findings, saying:
"If we can learn what has happened in the geological past, we can begin to use that knowledge to look into the future. Scientists engaged in climate change studies are advancing an important area of knowledge about the planet we live on."
