ALBERT

Description: Multibeam data were collected during RV Maria S. Merian cruise MSM95 (2020-09-09 – 2020-10-07). Multibeam sonar system was Kongsberg EM122. Data are unprocessed and may contain outliers and blunders and should not be used for grid calculations and charting projects without further editing. The raw multibeam sonar data in Kongsberg multibeam processing format (*.all) were recorded with Kongsberg SIS software running on Windows operating system. Kongsberg data files can be processed using the software packages CARIS HIPS/SIPS or with the open source software package MB-System.

Description: Multibeam data were collected with RV Polarstern along the route of cruise PS118 and data acquisition was continuously monitored during the survey. Multibeam sonar system was Teledyne/Atlas Hydrosweep DS3. SVPs were retrieved from CTD data from other working groups on board. SVPs were processed with HydrOffice SoundSpeedManager (https://www.hydroffice.org/soundspeed/main) and extended with World Ocean Atlas 13 (https://doi.org/10.7289/v5f769gt). SVP data were applied during acquisition. Multibeam data are unprocessed and may contain outliers and blunders and should not be used for grid calculations and charting projects without further editing. The raw multibeam sonar data in Teledyne/Atlas multibeam processing format (.asd) were recorded with Teledyne/Atlas Parastore software. Raw data files can be processed using software packages like CARIS HIPS/SIPS. For updated vessel configuration files check further details.

Description: Density-driven mass movement deposits (MMDs) were mapped throughout the Quaternary sedimentary record of Lake El'gygytgyn (NE Siberia) using high-resolution acoustic data. Three different acoustic facies types were identified in the lake: (1) pelagic sediment, (2) plastic flow deposits and (3) turbidites. Deposits from plastic flows are dominantly present proximal to the lakes' slopes, whereas deposits from turbidity currents occur more spatially distributed. During glacial times, the distribution of MMDs was more uniform, while during interglacial periods, MMDs were deposited predominantly close to the slope of the northwestern area. Furthermore, the overall number of MMDs and accumulated sediment volume significantly varies between glacial/interglacial periods. About 1.6 times more MMDs were mapped during interglacials, contributing to a 3.5 times higher sediment volume. The main reason for this large difference is that a significant increase in plastic flows were formed during interglacials, which account for a much larger volume of sediments when compared with the glacial intervals characterized by increased amount of turbidites. It appears that the most important source areas for MMDs are located at the northern and western shores. Cycles of lake level changes caused by variations in climate conditions between glacials and interglacials are likely the main trigger mechanism for the generation of these MMDs. The climate-dependent genesis and partly erosive potential influencing the sedimentary record contain implications to consider for future paleo-environmental reconstructions in lacustrine settings. The supplementary data include high resolution versions of the figures of the article, a spreadsheet with calculated data for the statistics presented, an archive of mapped horizons in the seismic data used for gridding and the reference profile AWI-20038540.