Antarctica is almost entirely covered by ice, in places over two miles thick. This ice hides a landscape that is less well known than the surface of Mars and represents one of Earth’s last unexplored frontiers. Ice-penetrating radar images provide a tantalizing glimpse of this landscape including mysterious entombed mountains larger than the European Alps and huge fjords twice as deep as the Grand Canyon. But radar cannot tell us when these features formed.
In the past, under warmer climate than today, the amount of ice on Antarctica waxed and waned leading to significant sea-level change. A key to understanding how ice will react to future warming climate and impact sea-level is being able to replicate how such ice reacted to known past warmer climate. To gain this understanding requires an accurate picture of the former landscape over which this ice first formed and flowed. This project tackles this goal using sand collected by previous sea-floor drilling expeditions off the coast of Antarctica. This sand was supplied from the continent interior by ancient rivers when it was ice-free over 34 million year ago, and later by glaciers.
The project will also study bedrock samples from rare ice-free parts of the Transantarctic Mountains. The primary activity is to apply multiple advanced dating techniques to single mineral grains contained within this sand and rock. Different methods and minerals yield different dates that provide insight into how Antarctica’s landscape has eroded over the many tens of millions of years during which sand was deposited offshore. Results from both the project and workshop will be disseminated through presentations at professional meetings, peer-reviewed publications, and through public outreach and media.