Antarctica went through heat wave 15.7 mn yrs ago

Scientists have revealed that Antarctica went through a heat wave nearly 15.7 million years ago during which plants and algae were abundant, a scientific breakthrough which would help in understanding climate change.

An international team, led by LSU Museum of Natural Science, has found evidence of the warm period in Antarctica that lasted for a few thousand years by analysing fossils.

Among the 1,107 meters of sediments recovered and analysed for microfossil content, a two-meter thick layer in the core displayed extremely rich fossil content.

This is unusual because the Antarctic ice sheet was formed about 35 million years ago, and the frigid temperatures there impede the presence of woody plants and blooms of dinoflagellate algae, the scientists said.

"We all analysed the new samples and saw 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.

"Together, these shifts in the microfossil assemblages represent a relatively short period of time during which Antarctica became abruptly much warmer," team leader Sophie Warny said.

According to the scientists, these palynomorphs, a term used to described dust-size organic material such as pollen, spores and cysts of dinoflagellates and other algae, provide hard evidence that Antarctica underwent a brief but rapid period of warming about 15 million years before present.

These startling results will offer new insight into Antarctica's climatic past -- insights that could potentially help climate analysts better understand the current climate change scenario, they said.

"This event will lead to a better understanding of global connections and climate forcing, in other words, it will provide a better understanding of how external factors imposed fluctuations in Earth's climate system.

"In the case of these results, the microfossils provide us with quantitative data of what the environment was actually like in Antarctica at the time, showing how this continent reacted when climatic conditions were warmer than they are today," Warny said.