USAP-DC

1043517/Clark

This award supports a project to develop a better understanding of the response of the WAIS to climate change. The timing of the last deglaciation of the western Ross Sea will be improved using in situ terrestrial cosmogenic nuclides (3He, 10Be, 14C, 26Al, 36Cl) to date glacial erratics at key areas and elevations along the western Ross Sea coast. A state-of-the art ice sheet-shelf model will be used to identify mechanisms of deglaciation of the Ross Sea sector of WAIS. The model results and forcing will be compared with observations including the new cosmogenic data proposed here, with the aim of better determining and understanding the history and causes of WAIS deglaciation in the Ross Sea. There is considerable uncertainty, however, in the history of grounding line retreat from its last glacial maximum position, and virtually nothing is known about the timing of ice- surface lowering prior to ~10,000 years ago. Given these uncertainties, we are currently unable to assess one of the most important questions regarding the last deglaciation of the global ice sheets, namely as to whether the Ross Sea sector of WAIS contributed significantly to meltwater pulse 1A (MWP-1A), an extraordinarily rapid (~500-year duration) episode of ~20 m sea-level rise that occurred ~14,500 years ago. The intellectual merit of this project is that recent observations of startling changes at the margins of the Greenland and Antarctic ice sheets indicate that dynamic responses to warming may play a much greater role in the future mass balance of ice sheets than considered in current numerical projections of sea level rise. The broader impacts of this work are that it has direct societal relevance to developing an improved understanding of the response of the West Antarctic ice sheet to current and possible future environmental changes including the sea-level response to glacier and ice sheet melting due to global warming. The PI will communicate results from this project to a variety of audiences through the publication of peer-reviewed papers and by giving talks to public audiences. Finally the project will support a graduate student and undergraduate students in all phases of field-work, laboratory work and data interpretation.

Person	Role
Pollard, David	Investigator
Curtice, Josh	Investigator
Clark, Peter	Investigator
Kurz, Mark D.	Co-Investigator

Antarctic Glaciology	Award # 1043517
Antarctic Glaciology	Award # 1043485
Antarctic Glaciology	Award # 1043018

NSIDC-0639_1
NSF-ANT10-43485_1
NSF-ANT10-43517

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea	None	exist
USAP-DC	Ice Sheet Model Output, West Antarctic Ice Sheet Deglaciation	None	exist

1. Nowicki, S., Bindschadler, R. A., Abe-Ouchi, A., Aschwanden, A., Bueler, E., Choi, H., … Wang, W. L. (2013). Insights into spatial sensitivities of ice mass response to environmental change from the SeaRISE ice sheet modeling project I: Antarctica. Journal of Geophysical Research: Earth Surface, 118(2), 1002–1024. (doi:10.1002/jgrf.20081)
2. Galeotti, S., DeConto, R., Naish, T., Stocchi, P., Florindo, F., Pagani, M., … Zachos, J. C. (2016). Antarctic Ice Sheet variability across the Eocene-Oligocene boundary climate transition. Science, 352(6281), 76–80. (doi:10.1126/science.aab0669)
3. Nowicki, S., Bindschadler, R. A., Abe-Ouchi, A., Aschwanden, A., Bueler, E., Choi, H., … Wang, W. L. (2013). Insights into spatial sensitivities of ice mass response to environmental change from the SeaRISE ice sheet modeling project II: Greenland. Journal of Geophysical Research: Earth Surface, 118(2), 1025–1044. (doi:10.1002/jgrf.20076)
4. Dutton, A., Carlson, A. E., Long, A. J., Milne, G. A., Clark, P. U., DeConto, R., … Raymo, M. E. (2015). Sea-level rise due to polar ice-sheet mass loss during past warm periods. Science, 349(6244), aaa4019–aaa4019. (doi:10.1126/science.aaa4019)
5. Pollard, D., DeConto, R. M., & Alley, R. B. (2015). Potential Antarctic Ice Sheet retreat driven by hydrofracturing and ice cliff failure. Earth and Planetary Science Letters, 412, 112–121. (doi:10.1016/j.epsl.2014.12.035)
6. Gomez, N., Pollard, D., & Mitrovica, J. X. (2013). A 3-D coupled ice sheet – sea level model applied to Antarctica through the last 40 ky. Earth and Planetary Science Letters, 384, 88–99. (doi:10.1016/j.epsl.2013.09.042)
7. Peterson, M. E., Saal, A. E., Kurz, M. D., Hauri, E. H., Blusztajn, J. S., Harpp, K. S., … Geist, D. J. (2017). Submarine Basaltic Glasses from the Galapagos Archipelago: Determining the Volatile Budget of the Mantle Plume. Journal of Petrology, 58(7), 1419–1450. (doi:10.1093/petrology/egx059)
8. Heinonen, J. S., & Kurz, M. D. (2015). Low-3He/4He sublithospheric mantle source for the most magnesian magmas of the Karoo large igneous province. Earth and Planetary Science Letters, 426, 305–315. (doi:10.1016/j.epsl.2015.06.030)