Repository logo
 

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

Simple item page
cam.issuedOnline2018-07-26
dc.contributor.authorHindshaw, RS
dc.contributor.authorAciego, SM
dc.contributor.authorTipper, ET
dc.contributor.orcidTipper, Edward [0000-0003-3540-3558]
dc.date.accessioned2018-10-03T04:44:31Z
dc.date.available2018-10-03T04:44:31Z
dc.date.issued2018
dc.description.abstractPermafrost 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. The U activity ratio provides information on water-rock interaction times and physical properties. We observe contrasting behavior between the two catchments. The highest U activity ratios and Li isotope values (those most distinct from bedrock) are observed in summer in the unglaciated catchment, when the active layer depth is expected to be at its maximum extent, whereas negligible seasonal variation and the lowest values are observed in the glaciated catchment. We therefore propose that the extent of solute acquisition is directly linked to the active layer depth, which is restricted in the glaciated catchment due to a layer of “dead ice” underneath the glacial outwash plain, and could therefore provide a valuable tool to assess changes in active layer depth at catchment scales.
dc.description.sponsorshipThis project was funded by a Swiss National Science Foundation fellowship for prospective researchers (PBEZP2-137335), a Marie Curie Intra-European Fellowship (PIEF-GA-2012-331501), and NERC Standard Grant NE/M001865/1. Fieldwork was supported by an Arctic Field Grant (219165/E10, The Research Council of Norway).
dc.identifier.doi10.17863/CAM.30423
dc.identifier.eissn2296-6463
dc.identifier.issn1863-4621
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/283061
dc.language.isoeng
dc.publisherFrontiers Media SA
dc.publisher.urlhttp://dx.doi.org/10.3389/feart.2018.00102
dc.rightsAttribution 4.0 International
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.subjectpermafrost
dc.subjectArctic
dc.subjectlithium isotopes
dc.subjecturanium isotopes
dc.subjectgeochemistry
dc.subjectweathering
dc.subjectactive-layer
dc.subjectglacier
dc.titleLi and U Isotopes as a Potential Tool for Monitoring Active Layer Deepening in Permafrost Dominated Catchments
dc.typeArticle
dcterms.dateAccepted2018-07-05
prism.publicationDate2018
prism.publicationNameFrontiers in Earth Science
prism.volume6
pubs.funder-project-idNatural Environment Research Council (NE/M001865/1)
rioxxterms.licenseref.startdate2018-07-26
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserved
rioxxterms.typeJournal Article/Review
rioxxterms.versionVoR
rioxxterms.versionofrecord10.3389/feart.2018.00102

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
feart-06-00102.pdf
Size:
2.21 MB
Format:
Adobe Portable Document Format
Description:
Published version
Licence
https://creativecommons.org/licenses/by/4.0/
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
DepositLicenceAgreement.pdf
Size:
417.78 KB
Format:
Adobe Portable Document Format
Download

Collections

Cambridge University Research Outputs