bathymetry; lakes; delta; natural hazards; sediment processes; mass movements
Reusch A., Moernaut J., Anselmetti F.S., Strasser M. (2016), Sediment mobilization deposits from episodic subsurface fluid flow—A new tool to reveal long-term earthquake records?, in Geology
, 44(4), 243-246.
Reusch Anna, Loher Markus, Bouffard Damien, Moernaut Jasper, Hellmich Franziska, Anselmetti Flavio S., Bernasconi Stefano M., Hilbe Michael, Kopf Achim, Lilley Marvin D., Meinecke Gerrit, Strasser Michael (2015), Giant lacustrine pockmarks with subaqueous groundwater discharge and subsurface sediment mobilizationGIANT LACUSTRINE POCKMARKS, in Geophysical Research Letters
, 42(9), 3465-3473.
Hilbe Michael, Anselmetti Flavio S. (2015), Mass Movement-Induced Tsunami Hazard on Perialpine Lake Lucerne (Switzerland): Scenarios and Numerical Experiments, in Pure and Applied Geophysics
, 172(2), 545-568.
Wüest Alfred, Anselmetti Flavio S., Arey J. Samuel, Ibelings Bastiaan W., Loizeau Jean-Luc, Vennemann Torsten, Lemmin Ulrich (2014), Into the abyss of Lake Geneva: the elemo interdisciplinary field investigation using the MIR submersibles, in Aquatic Sciences
, 76(S1), 1-6.
Kremer K., Marillier François, Hilbe Michael, Simpson Guy, Dupuy David, Ble J.F. Yrro, Rachoud-Schneider Anne-Marie, Corboud Pierre, Bellwald Benjamin, Wildi Walter, Girardclos Stéphanie (2014), Lake dwellers occupation gap in Lake Geneva (France–Switzerland) possibly explained by an earthquake–mass movement–tsunami event during Early Bronze Age, in Earth and Planetary Science Letters
, 385, 28-39.
Hilbe Michael, Anselmetti Flavio S. (2014), Signatures of slope failures and river-delta collapses in a perialpine lake (Lake Lucerne, Switzerland), in Sedimentology
, 61(7), 1883-1907.
Corella J. P., Arantegui A., Loizeau J. L., DelSontro T., le Dantec N., Stark N., Anselmetti F. S., Girardclos S. (2013), Sediment dynamics in the subaquatic channel of the Rhone delta (Lake Geneva, France/Switzerland), in Aquatic Sciences
, 76, 73-87.
Girardclos Stephanie et al (2012), Searching the Rhone delta channel in Lake Geneva since François-Alphonse Forel, in Archives des Sciences
, 65, 103-118.
Hilbe Michael, Anselmetti Flavio S., Eilertsen Raymond S., Hansen Louise, Wildi Walter (2011), Subaqueous morphology of Lake Lucerne (Central Switzerland): implications for mass movements and glacial history, in Swiss Journal of Geosciences
, 104(3), 425-443.
Kremer Katrina, Hilbe Michael, Simpson Guy, Decrouy Laurent, Wildi Walter, Girardclos Stéphanie, Reconstructing 4000 years of mass movement and tsunami history in a deep peri-Alpine lake (Lake Geneva, France-Switzerland), in Sedimentology
, in press.
This proposal seeks funds for the purchase of a multibeam sonar bathymetric device that is capable of acquiring high-resolution digital elevation models from lake or river floors with typical grid cells of few dm to 1 meter (similar or better than Lidar data on land). Such a device is currently not available in Switzerland and would provide a quantum leap in quality of subaquatic lake floor maps, as currently available data is usually several decades old and based on single-soundings with grid cells of 10s to 100s of meters.Numerous scientific questions and projects can only be addressed with such high-resolution lake floor data being available. The advantage of the ability to perform repeated measurements ('4D') allows determining time series of lake floor topographies, for instance in delta areas, so that sediment budgets influenced by large flood events can be quantified. Knowledge of erosional and depositional areas is crucial in predicting the future evolution of delta areas and to quantify how human land use in the catchment may affect the sediment budgets and delta morphologies. Furthermore, the device allows to extend the natural hazard maps made onshore to the subaquatic domain. Subaquatic slopes within lakes are frequently affected by mass movements and impacting rockfalls, both of which may be tsunamigenic. Multibeam bathymetric maps allow a basin-wide evaluation of areas prone to such mass movements, which, when combined with subsurface data from seismic surveying and sediment cores, allows to single out potential areas of future events. In addition, surface features of incipient slides, only detectable by high-resolution lake floor imagery, provide further evidence of current sublacustrine hazards. In a similar fashion, and as often shown in the marine environment (but barely in lakes), the device will allow location and investigations of subaquatic fluid seeps, such as mud volcanoes, pockmarks and subaquatic springs, which will allow precise sampling of composition and amounts of these fluids. Methane or CO2 released from such vents are not only crucial for the lake floor biological community but also for slope stability issues and, if the bubbles reach the lake's surface, for contribution of greenhouse gases to the atmosphere. Multibeam bathymetric data will further be a crucial prerequisite to locate neotectonic surface structures in lakes. Several areas will be investigated (e.g. Lake Neuchâtel) that are suspected to host seismically active faults. While it is difficult to locate such structures onshore, the calm lake floor environment offers an ideal area to search for these faults, eventually contributing to the currently heated debate on the neotectonic state of the Swiss perialpine region. Next to addressing these questions in lakes, such high-resolution data can also be acquired in rivers in order to show the temporal evolution of morphologies in river channels, i.e. during major flood event, a process critical in river restoration projects.Next to using the multibeam system in these applied research projects, we intend to push this fairly new technology forward by developing advanced data analysis and error estimation methodologies by a rigorous error modeling and quality assessment of the results. Moreover, establishing an active subaquatic beacon network will further increase the potential of the multibeam system by increasing the accuracy of 4D-surveys that will potentially allow determination of lake- and seafloor deformations as expected for instance in tectonically active areas.We propose SNF to cover 50 % of the acquisition costs for such a system and already have the remaining 50 % allocated from various institutions, i.e. Eawag, University of Geneva, ETHZ-Geodesy and Geodynamics Lab (GGL), and Landesanstalt für Umwelt, Messungen und Naturschutz Baden-Württemberg (representing their lake research institute on Lake Constance). The device will be available within the instrument pool for geophysical lake research equipment for the entire Swiss science community.