Active Projects: Grounding Line Forensics: The History of Grounding Line retreat in the Kamb Ice Stream Outlet Region (June 2006 - 2009)
GLF: The MovieParticipants:
Ginny Catania, The University of Texas at Austin
Jamin Greenbaum, The University of Texas at Austin
Christina Hulbe, Portland State University
Project Goals:
Understanding ice streams is a long-standing objective of West Antarctic glaciology. This field of study has progressed from recognizing ice streams' unique geologic setting and associated dynamics; to concern over the rate at which ice stream grounding lines retreat; to definition and location of upstream onsets and the discovery of tributary networks feeding into those onsets; and recently to the hotly debated possibility that the West Antarctic ice streams might be grinding to an interglacial halt. Understanding such processes has important influence over our ability to accurately predict mass balance changes in this region. Currently, one of the five major West Antarctic ice streams, Kamb, is quiescent, and another, Whillans, is slowing in its downstream reaches. The Kamb shut-down appears to have begun at its downstream end but beyond that simple observation, it is not possible, yet, to draw meaningful comparisons between the two adjacent streams. We do not know if current events on Whillans Ice Stream are similar to what transpired during the Kamb shut-down. The work proposed here intends to bridge that gap.
We will continue our previous efforts to identify and map ice surface and internal features that chronicle the sequence of events leading to the Kamb shut-down. In particular, we are interested in past grounding line migration and the relationship between that process and ice stream shutdown. The Kamb record, as we know it, indicates that the downstream reach is the first to change, and this makes sense, for reasons discussed later in this proposal. It is expected that this effort will yield useful insights into the influence of grounding line dynamics on ice stream flow. The work will involve a combination of field investigations using radio-echo sounding and GPS combined with computational efforts involving the interpretation of ice-surface features such as relict flow traces and crevasses.
Project Highlights:
We are back from our highly successful first field season. We found lots of interesting grounding line features including some evidence that the Kamb Ice Stream grounding line has jumped in position in the past. We will be spending the rest of the year analysing the data and preparing for our second season this coming November 2007. Joining us this year are the Polar-Palooza team who are interested in highlighting polar research to the public in the IPY.
