Sediment Transport on Arctic Shelves - Seasonal Variations in Suspended Particulate Matter Dynamics on the Laptev Sea Shelf (Siberian Arctic) = Sedimenttransport auf Arktischen Schelfen - Jahreszeitliche Schwankungen in der Schwebstoffdynamik auf dem Laptev-See-Schelf (sibirische Arktis)

• Main Author: Wegner, Carolyn
• Format: Thesis
• Language: English
• Published: Alfred-Wegener-Institut für Polar- und Meeresforschung 2003
• Subjects: Arctic; Laptev Sea; Arktis; Arktis*; Berichte zur Polar- und Meeresforschung; laptev
• Online Access: https://oceanrep.geomar.de/id/eprint/6687/; https://oceanrep.geomar.de/id/eprint/6687/1/Wegner-Diss_BerPolarforsch2003-455.pdf

The main objective of the study was to investigate seasonal sediment dynarnics on the Laptev Sea shelf. The Laptev Sea comprises one of the largest Siberian shelf areas and is characterized by seasonal ice coverage and thus, by a strong seasonality in sediment input. The pathways and the final fate of the sediments derived from the Siberian hinterland are central questions for understanding the complex land-shelf-ocean interactions and their seasonal variations. In order to characterize seasonal variations in suspended particulate matter (SPM) dynamics on the eastem Laptev Sea shelf, one-year Acoustic Doppler Current Profiler (ADCP) records and complementary optical backscatter profiles from the ice-free period were analyzed. In order to use indirect measuring devices for the quantification of SPM concentration, optical (turbidity meter) and acoustic (ADCP) backscatter sensors were compared to assess their potential for the investigation of SPM dynamics on the Laptev Sea shelf. To estimate SPM concentrations from optical backscatter signals, these were converted using the linear relation between the backscatter signals and SPM concentrations derived from filtered water samples. Applying the theoretical interaction of sound in the water to SPM, the acoustic backscatter signals were transformed adapting a previously established approach. SPM concentrations estimated from the backscattered signals of both sensors showed a close similarity to SPM concentrations obtained from filtered water samples. In general both the ADCPs and the turbidity meters provided good estimations, with ADCPs underestimating and turbidity meters slightly overestimating SPM concentrations. Hence, both sensors can be used for the deterrnination of SPM dynamics On the Laptev Sea shelf with its comparably low SPM concentrations. However, ADCPs are more convenient for investigation of sediment transport dynamics as they provide reasonable SPM concentration and current records for the entire water colurnn simultaneously. Combined turbidity ...