1. Subaqueous geomorphology and delta dynamics of Lake Brienz (Switzerland): implications for the sediment budget in the alpine realm
- Author
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Fabbri, Stefano C., Haas, Isabel, Kremer, Katrina, Motta, Danae, Girardclos, Stéphanie, and Anselmetti, Flavio S.
- Subjects
Alpine lake ,Megaturbidites ,Original Paper ,QE1-996.5 ,Quasi-4D refection seismic data ,Subaquatic delta channel ,Quasi-4D reflection seismic data ,550 Earth sciences & geology ,Geology ,Sediment budget - Abstract
Non-invasive techniques such as seismic investigations and high-resolution multibeam sonars immensely improved our understanding of the geomorphology and sediment regimes in both the lacustrine and the marine domain. However, only few studies provide quantifications of basin wide-sediment budgets in lakes. Here, we use the combination of high-resolution bathymetric mapping and seismic reflection data to quantify the sediment budget in an alpine lake. The new bathymetric data of Lake Brienz reveal three distinct geomorphological areas: slopes with intercalated terraces, a flat basin plain, and delta areas with subaquatic channel systems. Quasi-4D seismic reflection data allow sediment budgeting of the lake with a total sediment input of 5.54 × 106 t sediment over 15 years of which three-quarter were deposited in the basin plain. Lake Brienz yields extraordinarily high sedimentation rates of 3.0 cm/yr in the basin plain, much more than in other Swiss lakes. This can be explained by (i) its role as first sedimentary sink in a high-alpine catchment, and by (ii) its morphology with subaquatic channel-complexes allowing an efficient sediment transfer from proximal to distal areas of the lake., Swiss Journal of Geosciences, 114, ISSN:1661-8734, ISSN:1661-8726
- Published
- 2021
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