USAP-DC

The goal of this project is to drill and recover an ice core from Hercules Dome, Antarctica. The geographic setting of Hercules Dome makes it well-situated to investigate changes in the size of the West Antarctic ice sheet over long time periods. The base of the West Antarctic ice sheet lies below sea level, which makes this part of Antarctica vulnerable to melting from the relatively warm deep water of the Southern Ocean. An important research question is whether the West Antarctic Ice Sheet collapsed during Earth's last prolonged warm period, about 125,000 years ago, when the ocean was warmer and sea level was several meters higher than today. Evidence for or against such a collapse will be recorded in the chemistry and physical properties of the ice. The Hercules Dome ice core will be obtained over three to four field seasons in Antarctica using efficient drilling technology. This grant includes support for project management, pre-drilling science community engagement, ice-core recovery, and education and outreach activities.

Hercules Dome is located at the edge of the East Antarctic ice sheet, south of the Transantarctic Mountains at 86 degrees South, 105 degrees West. Glaciological conditions at Hercules Dome are simple, with well-defined layering to the bed, optimal for the recovery of a deep ice core reaching to the last interglacial period at depths between 1600 and 2800 meters. An ice core from Hercules Dome will provide a research opportunity for ice-core analysts and others to make progress on a number of science priorities, including the environmental conditions of the last interglacial period, the history of gases and aerosols, and the magnitude and timing of changes in temperature and snow accumulation over the last 150,000 years. Together with the network of ice cores obtained by U.S. and international researchers over the last few decades, results from Hercules Dome will yield improved estimates of the boundary conditions necessary for the implementation and validation of ice-sheet models critical to the projection of future Antarctic ice-sheet change and sea level.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Person	Role
Steig, Eric J.	Investigator and contact
Fudge, T. J.	Co-Investigator

Antarctic Glaciology	Award # 1841879
Antarctic Glaciology	Award # 1841858
Antarctic Glaciology	Award # 1841844

USAP-1841844_1

Deployment	Type
Hercules Dome	field camp

None in the Database

1. Fudge, T. J., Hills, B. H., Horlings, A. N., Holschuh, N., Christian, J. E., Davidge, L., Hoffman, A., O’Connor, G. K., Christianson, K., & Steig, E. J. (2022). A site for deep ice coring at West Hercules Dome: results from ground-based geophysics and modeling. Journal of Glaciology, 1–13. (doi:10.1017/jog.2022.80)
2. Davidge, L., Steig, E. J., & Schauer, A. J. (2022). Improving continuous-flow analysis of triple oxygen isotopes in ice cores: insights from replicate measurements. Atmospheric Measurement Techniques, 15(24), 7337–7351. (doi:10.5194/amt-15-7337-2022)
3. Davidge, L., Steig, E. J., & Schauer, A. J. (2022). Improving continuous-flow analysis of triple oxygen isotopes in ice cores: insights from replicate measurements. (doi:10.5194/egusphere-2022-60)
4. O’Connor, G. K., Holland, P. R., Steig, E. J., Dutrieux, P., & Hakim, G. J. (2023). Characteristics and rarity of the strong 1940s westerly wind event over the Amundsen Sea, West Antarctica. The Cryosphere, 17(10), 4399–4420. (doi:10.5194/tc-17-4399-2023)
5. O’Connor, G. K., Holland, P. R., Steig, E. J., Dutrieux, P., & Hakim, G. J. (2023). Drivers and rarity of the strong 1940s westerly wind event over the Amundsen Sea, West Antarctica. (doi:10.5194/tc-2023-16)