The ice-covered Antarctica of today was very different millions of years ago. It was a much warmer and wetter place, according to a study conducted by NASA.
According to the results of a recent study, taken in conjunction with that of an earlier piece of NASA research, it would appear the frozen wastelands of the Antarctica could be returning to the vastly different climate of all those millions of years ago, when it was warm enough to support vegetation and the growth of stunted trees.
A team of scientists from NASA's Jet Propulsion Laboratory in Pasadena, California and the Louisiana State University in Baton Rouge, examined plant leaf wax remnants in sediment core samples taken from under the Ross Ice Shelf. The team, lead by Sarah J. Feakins of the University of Southern California in Los Angeles, discovered that summer temperatures along the Antarctic coast, some 15 to 20 million years ago, were 20 degrees Fahrenheit higher than today and those temperatures used to go as high as 45 degrees Fahrenheit. It seems that even the precipitation levels were several times higher than that of today.
"The ultimate goal of the study was to better understand what the future of climate change may look like," said Feakins, an assistant professor of Earth sciences at the USC Dornsife College of Letters, Arts and Sciences. "Just as history has a lot to teach us about the future, so does past climate. This record shows us how much warmer and wetter it can get around the Antarctic ice sheet as the climate system heats up. This is some of the first evidence of just how much warmer it was."
According to the researchers, when study co-author Sophie Warny, an assistant professor at LSU, found large quantities of pollen and algae in the sediment cores in Antarctica, they suspected high-latitude temperatures during the middle Miocene epoch would have been warmer than previously thought. However, collecting samples of plant life in Antarctica is difficult as the massive ice sheets there grind and scrape away at everything while moving.
"Marine sediment cores are ideal to look for clues of past vegetation, as the fossils deposited are protected from ice sheet advances, but these are technically very difficult to acquire in the Antarctic and require international collaboration," according to Sophie.
While high carbon dioxide levels during the middle Miocene epoch have been documented in other studies through multiple lines of evidence, scientists are still not sure why carbon dioxide was at these levels during the middle Miocene. In fact, high levels of carbon dioxide, together with the global warmth documented from many parts of the world and now also from the Antarctic region, appear to coincide during this period in Earth's history.
Finally, according to the report, animals found in that era were "three-toed horses, deer, camel and various species of apes".
This research was funded by the U.S. National Science Foundation with additional support from NASA.
(Source: NASA)
