Hydrologic Coupling Between Glacier Ice and Periglacial Groundwater Systems
Permafrost regions are often influenced by past and/or present glacier ice. However, there is still much to be learned about the physical processes that connect subglacial and proglacial hydrology to the hydrological systems of periglacial landscapes. This work builds upon intensive prior research on the Greenland Ice Sheet’s basal boundary and associated groundwater system to enhance understanding of coupled ice sheet, groundwater, and surface water hydrological processes.
Several research themes address hydrologic connectivity, spanning near-field and far-field length scales and covering time scales from instantaneous to ice age cycles. At the near-field and short time scales, field measurements and modeling investigations are being used to derive the various components of pressure forcing from the ice sheet on the underlying and adjacent groundwater system, including ice loading and subglacial drainage evolution. Far-field investigations utilize in situ observations and numerical simulations to study the generation of basal melt from sliding friction and geothermal heat flux, and the fate of the resulting meltwater (whether it is stored, recharges groundwater, or is routed to proglacial outflow). At the ice age time scale, a transient thermomechanical ice sheet model examines the time-space migration of melted bed conditions (groundwater recharge area) over a cycle of ice sheet retreat.
Motivated by the need for safety assessments of potential deep geologic repository site conditions, overarching results of the three research themes will advance conceptualizations and numerical simulations of coupled ice and periglacial hydrologic processes over relevant time scales.
Team
Joel Harper, University of Montana, USA
Publications
Saito, J., Meierbachtol, T., and Harper, J. (2022). Multi-decadal elevation changes of the land terminating sector of West Greenland. Journal of Glaciology, 1–9, doi: 10.1017/jog.2022.47.
Stansberry, A., Harper, J., Johnson, J. V., & Meierbachtol, T. (2022). Millennial-scale migration of the frozen / melted basal boundary, western Greenland Ice Sheet. Journal of Glaciology, 1–10, doi: 10.1017/jog.2021.134.
Liljedahl, L. C., Meierbachtol, T., Harper, J., van As, D., Näslund, J.-O., Selroos, J.-O. (2021). Rapid and sensitive response of Greenland’s groundwater system to ice sheet change. Nature Geoscience, 14, 751-755, doi: 10.1038/s41561-021-00813-1.
Harper, J., Meierbachtol, T., Humphrey, N., Saito, J., and Stansberry, A. (2021). Generation and fate of basal meltwater during winter, western Greenland Ice Sheet. The Cryosphere, 15(12), 5409–5421, doi: 10.5194/tc-15-5409-2021.