Wilkes Land Sediment Cores Help Scientists Understand Past Dramatic Antarctic Climate Change
30.04.2010 - Atmosphere & Space, Ice & Snow, Antarctic
A recent research expedition in Antarctic waters could yield critical clues to understand how some 53 million years ago Antarctica switched from a warm, sub-tropical environment to its current icy state. In a mere 400,000 years, concentrations of atmospheric carbon dioxide on the continent decreased as global temperatures dropped and ice sheets formed.
To find out why, an international team of scientists participating in the Wilkes Land Glacial History Expedition spent two months at sea aboard the JOIDES Resolution to retrieve sediment cores from the seafloor off the coast of Antarctica. These sediments, up to 2,000 metres long, are essential to the research as archives of the Antarctic Ice Sheet.
Going back some 53 million years, the new core samples provide the world's first direct record of waxing and waning of ice in this region of Antarctica. When combined, the cores help the scientists gain better insight into the transition of Antarctica from a sub-tropical greenhouse world to its current icy self.
Furthermore, the sediments and microfossils preserved within the cores will provide more detailed information on the start of cooling and the development of the first Antarctic glaciers, as well as the progression and retreat of the Antarctic ice sheets. Gaining better insight into the behavior of the ice sheets is important for building effective global climate models to predict future climate.
Now the team will begin a multi-year process of on-shore analyses to further investigate the Wilkes Land cores. In doing so, they will find important age constraints to refine models of Antarctic ice sheet development and evolution, forming the basis for models of future ice sheet behaviour and polar climate change.
