614.1 Branch Seminar Series: MIchael Studinger

Lamont-Doherty Earth Observatory of Columbia University

In the last decade our picture of Antarctica has been radically altered. The discovery of a complex pattern of ice flow, extending deep into the interior of East Antarctica, has challenged the view that the Antarctic Plateau is a slow-moving, homogeneous region. More than 150 subglacial lakes are buried beneath several kilometers of ice ranging in size from Lake Ontario to Manhattan. Together these lakes form a subglacial hydrosphere that provides a unique habitat for microbial ecosystems. Acting as a lubricant, the network of subglacial lakes and streams is a crucial component in the long-term stability and dynamic behavior of the overlying ice sheet. The flow of water between these lakes on timescales of several years indicates an active dynamic environment beneath that Antarctic ice sheet. Identifying and quantifying the complex glaciologic, hydrologic, and tectonic processes that constitute the subglacial environment remains one of the biggest challenges in polar research. Airborne geophysical surveys consisting of laser scanning, ice-penetrating radar, gravity and magnetic measurements are the most efficient way to image the subglacial environment over large areas. Combined with spaceborne measurements, aerogeophysical data are a powerful tool for detecting and monitoring the accelerating changes in the cryosphere.