Seismic hazard; Mass transport deposit; Lake sediments; Paleoearthquake magnitude and source; Turbidites; Paleoseismology
Strupler M., Danciu L., Hilbe M., Kremer K., Anselmetti F. S., Strasser M., Wiemer S. (2018), A subaqueous hazard map for earthquake-triggered landslides in Lake Zurich, Switzerland, in Natural Hazards
, 90(1), 51-78.
Strupler Michael, Danciu Laurentiu, Hilbe Michael, Kremer Katrina, Anselmetti Flavio S, Strasser Michael, Wiemer Stefan (2018), A subaqueous hazard map for earthquake-triggered landslides in Lake Zurich, Switzerland, in Natural Hazards
Kremer Katrina, Wirth Stefanie B., Reusch Anna, Fäh Donat, Bellwald Benjamin, Anselmetti Flavio S., Girardclos Stéphanie, Strasser Michael (2017), Lake-sediment based paleoseismology: Limitations and perspectives from the Swiss Alps, in Quaternary Science Reviews
, 168, 1-18.
Kremer Katrina, Usman Muhammed O., Satoguchi Yasufumi, Nagahashi Yoshitaka, Vadakkepuliyambatta Sunil, Panieri Giuliana, Strasser Michael (2017), Possible climate preconditioning on submarine landslides along a convergent margin, Nankai Trough (NE Pacific), in Progress in Earth and Planetary Science
, 4(1), 20.
Earthquake can initiate subaquatic mass transport and sediment deformation structures, the deposits of which are stored in the sedimentary archive. Due to their good preservation potential and improving dating methods, these earthquake-related deposits in the sedimentary archive of lakes can extend the earthquake catalogue back to prehistorical times. The determination of frequency, epicentre and magnitude of these paleoearthquakes can be a key input for improving a probabilistic seismic hazard model, especially in areas such as Switzerland where strong earthquakes have long recurrence rates and might not be recorded in historic times. In order to better interpret the prehistorical earthquake-related sedimentary record, it remains important to understand which historical earthquakes did trigger mass transport deposits and sediment deformation structures, and which earthquakes did not trigger secondary sedimentary effects in the lake basins. The proposed project is aimed to improve our fundamental understanding of which earthquakes, or what kind of shaking, leave traces in the sediments, in order to evaluate the completeness of the sublacustrine paleoseismological record, using Lake Thun as example. The Kander River Deviation into Lake Thun in 1714 AD can be traced over the entire lake basin and thus, represent a good stratigraphic marker to date the sediments. This deviation caused a ~ 6 time increase in sedimentation rate generating higher sensitivity to earthquakes, as it has been shown in a previous study. Since 1714 AD, several historical earthquakes triggered mass-transport deposits are recorded in Lake Thun. We propose to collect new data to cover the pre-1714 AD phase. Furthermore, by modelling the isoseismic maps of the historical earthquakes for the periods covered by the studied sediments, the intensity threshold ranges for mass transport and sediment deformation structures will be determined. The second aim of this project, directly linked to the first one, is to compare the paleoseismological record with the contemporary national seismic hazard model of Switzerland, updated in 2015. Thus, using the intensity ranges determined in the first part of this project and using the paleoseismic database of Switzerland a systematic analysis of frequencies, sources and magnitudes of possible paleoearthquakes will be compared to time series produced by the seismic hazard model of Switzerland. This allows a sanity check on the hazard model using ‘precariously balanced slopes’, much in the same way that in the US, precariously balanced rocks have been used.