T39 The Cryosphere & Mountain Hydrology, Past and Present and Future (Posters)

Sunday, 22 September 2024
8:00 AM - 5:30 PM
Hall D

GEOCHEMICAL TRACERS TO INVESTIGATE WATERSHED AND PERMAFROST DYNAMICS IN ALASKA'S NORTH SLOPE

Paper number: T39-4
Program: Technical Sessions
Time: 8:00 AM – 5:30 PM

Authors

Abstract

The rapid pace of climate change in the Arctic is dramatically impacting permafrost-dominated watersheds. Understanding these systems' hydrological and biogeochemical responses to warming is critical for informing Arctic communities and ecosystems and constraining global carbon and water fluxes. This study aims to characterize the impact of seasonality and climate change on groundwater discharge and transport in rivers underlain by permafrost in the North Slope of Alaska. This study will utilize deuterium/hydrogen (δD) and oxygen-18/oxygen-16 (δ18O) stable isotopic ratios of water and the dissolved uranium isotopic composition (234U/238U) to characterize hydrology and water-rock interaction time of watersheds underlain by permafrost. This project will examine variations caused by seasonal permafrost thaw/freeze dynamics, as well as elucidate the source of groundwater discharge and assess major cation and trace metal release from permafrost thaw or the overlaying active layer. Fieldwork, conducted in close proximity to the Toolik Field Station, will involve collecting water samples in watershed drainages and monitoring active layer thickness throughout freeze and thaw seasons. This study employs a multi-faceted approach, including sediment flux measurements, isotopic analysis, and thaw depth monitoring. Results aim to demonstrate the utility of a coupled uranium and water isotope approach to characterizing climate-induced shifts in active layer deepening and permafrost-derived material transport in Arctic rivers.

Geological Society of America Abstracts with Programs. Vol. 56, No. 5

doi: 10.1130/abs/2024AM-405542

© Copyright 2024 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.