Vulnerability of East Antarctic ice streams to warm ocean water incursions
This project will determine the potential vulnerability of key ice streams to incursions of warmer ocean water onto the continental shelf and if this mechanism could already explain any of the observed thinning of the ice sheet. It will provide important constrains on ice dynamic of the investigated section of the EAIS, and thus will be critical for future ice sheet models and provide mechanisms for EAIS contributions to past sea level high-stand. The PI proposes to investigate four key ice stream systems on the continental shelf between ~90°E and 160°E. They will use multibeam bathymetry to identify if and where cross-shelf troughs exist to help determine whether these troughs could provide potential pathways for warmer ocean water. Furthermore, detailed analysis of morphological features of these troughs could provide information on past ice dynamic, maximum extent, and flow direction of related paleo ice streams. The PIs will also conduct water column measurements along these troughs and on the continental slope to determine whether warmer ocean water could enter the shelf in the near future, or if such water has already entered any troughs, and thus might be causing the observed thinning of some ice streams.
The main data acquisiton happend during the expedition NBP1503 with the US icebreaker NB Palmer from March 24 to May 3 2016. Figure 1 shows the route the expedition took.
Figure 1: Shiptrack of the expedition NBP1503.
During this expedition we collected multibeam bathymetry data, water samples, and conducted oceanographic measurements to establish the seafloor morphology and and the water column structure along the continental margin.
Details of the expedition can be found at the blogs
- Williams, G. D., A.D. Fraser, A. Lucieer, D. Turner, E. Cougnon, P. Kimball, T. Toyota, T. Maksym, H. Singh, F. Nitsche, and M. Paget, 2016. Drones in a cold climate, Eos, 97, doi:10.1029/2016EO043673.
- Nitsche, FO, R. Guerrero, G. Williams, D. Porter, E. Cougnon, A. D. Fraser, R. Correia, D. Richardson (2015). Access of warm Southern Ocean water along the East Antarctic Margin - first results from the NBP1503 cruise. AGU Fall meeting 2015, C21A-0694. San Francisco, CA, USA, 15. December 2015 (poster).
Outreach and Educational Resources
As part of this project a PolarTREC Dominque Richardsonteacher/educator participate in the expeditions and created various outreach material:
In February 2016 Frank Nitsche presented some science background about "Melting of the Antarctic Ice Sheets– Ice and ocean interaction: consequences for sea-level rise” to science teachers from the NY-NJ metropolitan area as part of the Earth2Class program.
Additional educational links and materials can be found at the event's website.
This project is funded by NSF OPP (grant #1245879)