Evidence Antarctic Used to Be a Lot Warmer Found in Ice Core
01.10.2009 - Ice & Snow, Flora & Fauna, Other, Antarctic
Algae and pollen were found in the latest ice core samples taken by theAntarctic Geologic Drilling Program (ANDRILL). Theirpresence provides hard evidence that it was once a lot warmer duringAntarctica's history. The breakthrough findings were made by Dr. Sophie Warny, Louisiana State University assistant professor of geology and geophysics andcurator at the LSU Museum of Natural Science, before being confirmed by her ANDRILL colleagues in the international collaborative study.
Although scientists from other nations had found an increase in pollen grains of woody plants in the layer right above it, no layer features such a presence of algae. The unique consistency of the two-metre thick layer had been noticed before, but was then simply labeled as a diatomite (a layer rich in fossils and diatoms).
After a more thorough analysis, the layer was found to show a "2,000-fold increase in two species of fossil dinoflagellate cysts, a five-fold increase in freshwater algae and up to an 80-fold increase in terrestrial pollen" according to Warny. This material shows that some 15 million years in the past, Antarctica saw a short but intense period of warming, during which the average temperature in January reached 10°C and sea surface temperatures ranged between 0°C and 11.5°C.
With this new quantitative data, scientists have now an opportunity to understand how Antarctica reacted to warming climate conditions in the past and to fine tune their predictions for how the continent will react to current climate change. The integration of this new data into existing ice sheet and climate models will enhance their ability to reproduce past climate conditions and better predict future climate changes.
