USAP-DC

The evolution of surface and shallow subsurface meltwater across Antarctic ice shelves has important implications for their (in)stability, as demonstrated by the 2002 rapid collapse of the Larsen B Ice Shelf. It is vital to understand the causes of ice-shelf (in)stability because ice shelves buttress against the discharge of inland ice and therefore influence ice-sheet contributions to sea-level rise. Ice-shelf break-up may be triggered by stress variations associated with surface meltwater movement, ponding, and drainage. These variations may cause an ice shelf to flex and fracture. This four-year project will provide key geophysical observations to improve understanding of ice-shelf meltwater and its effects on (in)stability. The work will be conducted on the George VI Ice Shelf on the Antarctic Peninsula, where hundreds of surface lakes form each summer.

Over a 27-month period, global positioning systems, seismometers, water pressure transducers, automatic weather stations, and in-ice thermistor strings will be deployed to record ice shelf flexure, fracture seismicity, water depths, and surface and subsurface melting, respectively, in and around several surface lakes on the George VI Ice Shelf, within roughly 20 km of the British Antarctic Survey's Fossil Bluff Station. Field data will be used to validate and extend the team's approach to modelling ice-shelf flexure and stress, and possible "Larsen-B style" ice-shelf instability and break-up.

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
Banwell, Alison	Investigator and contact
Macayeal, Douglas	Co-Investigator

Antarctic Glaciology	Award # 1841607
Antarctic Glaciology	Award # 1841467

USAP-1841607_1

Deployment	Type
Alison Banwell	field camp
Douglas Macayeal	general deployment
Ian Willis	field camp
Laura Stevens	field camp
Rebecca Dell	field camp

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	Dataset for: Banwell et al. 2024, 'Observed meltwater-induced flexure and fracture at a doline on George VI Ice Shelf, Antarctica', Journal of Glaciology.	ZIP Archive	exists

1. Banwell, A. F., Datta, R. T., Dell, R. L., Moussavi, M., Brucker, L., Picard, G., … Stevens, L. A. (2021). The 32-year record-high surface melt in 2019/2020 on the northern George VI Ice Shelf, Antarctic Peninsula. The Cryosphere, 15(2), 909–925. (doi:10.5194/tc-15-909-2021)
2. Dunmire, D., Lenaerts, J. T. M., Banwell, A. F., Wever, N., Shragge, J., Lhermitte, S., Drews, R., Pattyn, F., Hansen, J. S. S., Willis, I. C., Miller, J., & Keenan, E. (2020). Observations of Buried Lake Drainage on the Antarctic Ice Sheet. Geophysical Research Letters, 47(15). Portico. https://doi.org/10.1029/2020gl087970 (doi:10.1029/2020gl087970)
3. Coffey, N. B., MacAyeal, D. R., Copland, L., Mueller, D. R., Sergienko, O. V., Banwell, A. F., & Lai, C.-Y. (2022). Enigmatic surface rolls of the Ellesmere Ice Shelf. Journal of Glaciology, 1–12. https://doi.org/10.1017/jog.2022.3 (doi:10.1017/jog.2022.3)
4. Banwell, A. F., Wever, N., Dunmire, D., & Picard, G. (2023). Quantifying Antarctic‐Wide Ice‐Shelf Surface Melt Volume Using Microwave and Firn Model Data: 1980 to 2021. Geophysical Research Letters, 50(12). Portico. https://doi.org/10.102/2023gl102744 (doi:10.1029/2023gl102744)
5. Taylor, A. G., Seligman, D. Z., Hainaut, O. R., & Meech, K. J. (2023). Fitting the Light Curve of 1I/‘Oumuamua with a Nonprincipal Axis Rotational Model and Outgassing Torques. The Planetary Science Journal, 4(10), 186. (doi:10.3847/psj/acf617)
6. Nekrasov, P., & MacAyeal, D. R. (2023). Ocean wave blocking by periodic surface rolls fortifies Arctic ice shelves. Journal of Glaciology, 1–11. (doi:10.1017/jog.2023.58)
7. Dunmire, D., Banwell, A. F., Wever, N., Lenaerts, J. T. M., & Datta, R. T. (2021). Contrasting regional variability of buried meltwater extent over 2 years across the Greenland Ice Sheet. The Cryosphere, 15(6), 2983–3005. (doi:10.5194/tc-15-2983-2021)
8. Glen, E., Leeson, A. A., Banwell, A. F., Maddalena, J., Corr, D., Noël, B., & McMillan, M. (2024). A comparison of supraglacial meltwater features throughout contrasting melt seasons: Southwest Greenland. (doi:10.5194/egusphere-2024-23)
9. Dunmire, D., Wever, N, Banwell., A.F. Lenaerts, J. 2024, “Future (2015-2100) Antarctic-wide ice-shelf firn air depletion from a statistical firn emulator”, Nature Communications Earth and Environment. 5, 100 (2024). (doi:10.1038/s43247-024-01255-4)
10. Banwell., A.F., Willis, I.C., Stevens, L.A., Dell, R.L. and MacAyeal, D.R., in press, Observed meltwater-induced flexure and fracture at a doline on George VI Ice Shelf, Antarctica. Journal of Glaciology.
11. Ochwat, N. E., Scambos, T. A., Banwell, A. F., Anderson, R. S., Maclennan, M. L., Picard, G., Shates, J. A., Marinsek, S., Margonari, L., Truffer, M., & Pettit, E. C. (2024). Triggers of the 2022 Larsen B multi-year landfast sea ice breakout and initial glacier response. The Cryosphere, 18(4), 1709–1731. (doi:10.5194/tc-18-1709-2024)
12. Ochwat, N. E., Scambos, T. A., Banwell, A. F., Anderson, R. S., Maclennan, M. L., Picard, G., Shates, J. A., Marinsek, S., Margonari, L., Truffer, M., & Pettit, E. C. (2023). Triggers of the 2022 Larsen B multi-year landfast sea ice break-out and initial glacier response. (doi:10.5194/tc-2023-88)