Science Projects: LISSARD
LISSARD: Lake and Ice Stream Subglacial Access Research Drilling
Overview: Water Sloshing About an Ice-Covered Continent
The LISSARD project (Lake and Ice Stream Subglacial Access Research Drilling) is one of three research components of the WISSARD integrative initiative (Whillans Ice Stream Subglacial Access Research Drilling) that is being funded by the Antarctic Integrated System Science Program of NSF's Office of Polar Programs, Antarctic Division. LISSARD focuses on the role of active subglacial lakes in determining how fast the West Antarctic ice sheet loses mass to the global ocean and influences global sea level changes. The existence and importance of active subglacial lakes in Antarctica has been recognized just recently, and the lakes have been identified as high priority targets for scientific investigations. Until about five years ago scientists thought that subglacial lakes exist as huge, but isolated, 'bubbles' of water trapped in deep depressions carved in bedrock by moving ice. However, recent discoveries of active subglacial lakes (more than 120 have been identified in Antarctica), which are pumping water in and out on time scales of months to years, demonstrates that many subglacial lakes are part of an interconnected system of water drainage.
Science Problem: Will Subglacial Water Cause Ice Streams to Slip-Slide Away?
LISSARD researchers will spend five years collecting and synthesizing data on active subglacial lakes using an unprecedented array of scientific techniques, including satellite remote sensing, surface geophysics, borehole sensors, as well as laboratory analyses of subglacial water, sediment, and basal ice samples. This uniquely comprehensive set of observations will make it possible to improve computer models of ice sheet dynamics by introducing realistic treatments of subglacial water flow and its control on fast ice motion. In addition, samples of subglacial sediments and basal ice will provide an opportunity to study the history and evolution of Antarctic subglacial lakes and of the ice sheet itself. LISSARD investigators will integrate their science with the two other components of WISSARD. They will provide constraints on physical characteristics of subglacial environments to GBASE colleagues and help clarify the importance of subglacial water and sediments fluxes in stability of grounding zone environments investigated by RAGES.
Project Significance and Impacts:
The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the West Antarctic Ice Sheet (WAIS) alone would contribute 10-16 feet to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations.
After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community, and assets will be accessible for future use through the NSF-OPP drilling contractor. Construction of the subglacial lake drill and LISSARD science instrumentation will enhance high-level skills and know-how in the US polar engineering community. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007).
LISSARD scientists are integrated into the WISSARD Education and Outreach program. The project will train a cohort of new young scientists in a setting of multidisciplinary, integrated Antarctic science with heavy student involvement in development and application of advanced technologies to Antarctic field research. Furthermore, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be the last unexplored aquatic environments on Earth. In these efforts, LISSARD scientists will be supported by experienced K-12 educators, informal educators, and renowned science journalists, some of whom will have the opportunity to report from the field during the first penetration of a subglacial lake in 2011-12.