Permafrost Hydrogeology of Taylor Valley, Antarctica: Insights From Deep Electrical Resistivity Tomography
Geophysical Research Letters | 2024-09-28 | Journal article | DOI: 10.1029/2023GL106912
During the austral summer of 2020, we conducted an electrical resistivity survey in Taylor Valley, McMurdo Dry Valleys, Antarctica, to map the thickness of permafrost, determine its lower boundaries and identify the presence and connectivity of saline groundwater at depth. Results show a complex distribution of permafrost, with layers of saline groundwater at different levels. We recognized two distinct zones: one of low resistivity around Lake Fryxell, related to the presence of two systems of brines at different depths, and the other displaying typical ice-rich frozen ground resistivity values near Coral Ridge. These findings reveal variations in permafrost thickness and brine depth along the valley, both horizontally and vertically. Our research identifies a multi-level groundwater circulation system: a shallow, local network, connected to surface water bodies like Lake Fryxell, above a deeper, regional system.
Credits
CNR (PNRA 2018 N° 00253 Profile D, prot.73633/2019, SENECA PROJECT: Source and origin of greenhouses gases in Antarctica).