A new approach for reconstructing glacier variability based on lake sediments recording input from more than one glacier

• Published in: Quaternary Research
• Main Authors: Vasskog, Kristian, Paasche, Øyvind, Nesje, Atle, Boyle, John F., Birks, H.J.B.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2012
• Subjects: Norway; glacier
• Online Access: http://dx.doi.org/10.1016/j.yqres.2011.10.001; http://api.elsevier.com/content/article/PII:S0033589411001256?httpAccept=text/xml; http://api.elsevier.com/content/article/PII:S0033589411001256?httpAccept=text/plain; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400008279

We explore the possibility of building a continuous glacier reconstruction by analyzing the integrated sedimentary response of a large (440 km 2 ) glacierized catchment in western Norway, as recorded in the downstream lake Nerfloen (N61°56’, E6°52’). A multi-proxy numerical analysis demonstrates that it is possible to distinguish a glacier component in the ~ 8000-yr-long record, based on distinct changes in grain size, geochemistry, and magnetic composition. Principal Component Analysis (PCA) reveals a strong common signal in the 15 investigated sedimentary parameters, with the first principal component explaining 77% of the total variability. This signal is interpreted to reflect glacier activity in the upstream catchment, an interpretation that is independently tested through a mineral magnetic provenance analysis of catchment samples. Minimum glacier input is indicated between 6700–5700 cal yr BP, probably reflecting a situation when most glaciers in the catchment had melted away, whereas the highest glacier activity is observed around 600 and 200 cal yr BP. During the local Neoglacial interval (~ 4200 cal yr BP until present), five individual periods of significantly reduced glacier extent are identified at ~ 3400, 3000–2700, 2100–2000, 1700–1500, and ~ 900 cal yr BP.