Li and U Isotopes as a Potential Tool for Monitoring Active Layer Deepening in Permafrost Dominated Catchments ...

• Main Authors: Hindshaw, RS, Aciego, SM, Tipper, ET
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers Media SA 2018
• Subjects: permafrost; Arctic; lithium isotopes; uranium isotopes; geochemistry; weathering; active-layer; glacier; Svalbard
• Online Access: https://dx.doi.org/10.17863/cam.30423; https://www.repository.cam.ac.uk/handle/1810/283061

Permafrost in the Arctic is decreasing in extent and the depth of the seasonally thawed layer, the active layer, is increasing. Increased exposure to water is increasing fluxes of organic and inorganic solutes with potential impacts for the global carbon cycle and downstream ecosystems. Understanding the relationship between solute release and active layer depth will be critical for modeling environmental impact, especially in inaccessible regions where there is a lack of data. In this study, we focus on the potential for the isotopes of lithium (Li) and uranium (U) to track active layer extent in two permafrost-dominated catchments in Svalbard: one glaciated and one unglaciated. These isotope systems can be measured to a much higher precision than concentration measurements and act as sensitive tracers of environmental change. The extent of Li isotope fractionation provides information on the balance between dissolution of primary phases and formation of secondary phases, such as clay minerals and oxides. ...