Hydrologic properties of a highly permeable firn aquifer in the Wilkins Ice Shelf, Antarctica

Lynn Montgomery; C. Miege; Julie MIller; Bruce Wallin; Ted A. Scambos; Olivia L. Miller; D Kip Solomon; Richard Forster; Lora Koenig

doi:10.1029/2020gl089552

USGS · 70215672

Hydrologic properties of a highly permeable firn aquifer in the Wilkins Ice Shelf, Antarctica

Lynn Montgomery·C. Miege·Julie MIller·Bruce Wallin·Ted A. Scambos·Olivia L. Miller·D Kip Solomon·Richard Forster·Lora Koenig

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Abstract

We present measurements of the density, hydraulic conductivity, and specific discharge of a widespread firn aquifer in Antarctica, within the Wilkins Ice Shelf. At the field site, the aquifer is 16.2 m thick, starting at 13.4 m from the snow surface and transitioning from water‐saturated firn to ice at 29.6 m. Hydraulic conductivity derived from slug tests show a geometric mean value of 1.4 ± 1.2 × 10 −4 m s −1 , equivalent to permeability of 2.6 ± 2.2 × 10 −11 m 2 . A borehole dilution test indicates an average specific discharge value of 1.9 ± 2.8 × 10 −6 m s −1 . Ground‐penetrating radar profiles and a groundwater flow model show the aquifer is draining laterally into a large nearby rift. Our findings indicate that the firn aquifer in the vicinity of the field site is likely not in a steady state and its presence likely contributed to past ice shelf instability.

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Geophysical Research Letters Article

Source-reported bounding extent: -71.79883675782347° to -71.54143894204527° latitude; -71.54022216796875° to -70.400390625° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Lynn Montgomery, C. Miege, Julie MIller, Bruce Wallin, Ted A. Scambos, Olivia L. Miller, D Kip Solomon, Richard Forster, Lora Koenig. 2020-11-15. Hydrologic properties of a highly permeable firn aquifer in the Wilkins Ice Shelf, Antarctica. https://doi.org/10.1029/2020gl089552

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