Glacial Hydrochemistry

Modern remote sensing of subglacial environments beneath the Antarctic and Greenland Ice Sheets reveals dynamic hydrologic systems, where water is stored in lakes and saturated sediments and periodically flushed toward the ice sheet margins. These systems regulate ice flow and supply solutes and nutrients to the ocean, but are challenging to characterize directly due to extensive ice cover. My research uses geochronological, geochemical, and textural analyses of sedimentary archives from subglacial and proglacial environments to reconstruct biogeochemical processes and environmental conditions beneath and in front of ice sheets.

Subglacial Hydrology

I have ongoing projects focused on establishing long-term records of subglacial flushing beneath the East Antarctic Ice Sheet. In a recent study, we presented the first well-dated, millennial-scale record of Antarctic basal flushing. Using sedimentary analyses paired with U-series geochronology and stable isotope geochemistry, we demonstrated that subglacial water flow beneath the David Glacier catchment increased during warm climate periods. This work links centennial-scale climate change with subglacial hydrology, which may be an important process governing ice motion.Read about this work in our recent preprint.

Carbon Cycling Beneath Ice Sheets

Tsolated subglacial environments may contain vast stores of carbon dioxide and methane, which are prone to release during deglaciation. However, carbon cycling beneath the Antarctic ice sheet remains poorly constrained. In our work on Antarctic basal carbonate samples, we demonstrate that microbial respiration of organic matter is a widespread process producing CO₂ beneath the East Antarctic Ice Sheet.

In another project, we present the first evidence of subglacial thermogenic methane production in Antarctica. Through combined carbonate geochemistry and lipid biomarker analyses, we show that thermogenic methane accumulated in basal hydrocarbon seeps in the David Glacier Catchment and the Pensacola Mountains during Pleistocene deglacial periods. Read more about this work in our preprint.