- 1ISTerre, University Grenoble Alpes, Grenoble, France
- 2Geolithe, Crolles, France
Landslides are difficult to predict and can therefore be a serious threat to populations and infrastructures. Understanding landslide processes and their precursor parameters is an important challenge for scientists and for public managers. Landslide monitoring is essential for determining the hazard associated with the unstable slopes. Computing seismic velocity changes from ambient seismic noise has been proven an effective tool for landslide monitoring. Before failure, a drop in rigidity in the landslide leads to a decrease in shear wave velocity, creating a potential precursory signal that can be retrieved by seismic interferometry (1). An important step is distinguishing these precursory signals from environmental influences on the seismic velocities that are often observed.
The Séchilienne landslide, located 25 km southeast of Grenoble, has been instrumented with broadband seismic stations since 2013 (2). We use this extensive dataset to compute relative seismic velocity changes (dV/V) from ambient seismic noise over a period of 10 years. We observe seasonal cycles that could be associated with the thermomechanical state of the slope and/or the water table fluctuations. These seasonal cycles are most prominent in low frequency ranges (2–8 Hz). The dV/V fluctuations remain in a range of a few percents. In particular, no significant velocity drop was observed, which is coherent with no observed sudden acceleration within these 10 years.
This work was partially funded by the European Research Council (ERC) under grant No. 101142154 - Crack The Rock project.
(1) Mainsant, G., E. Larose, C. Brönnimann, D. Jongmans, C. Michoud, and M. Jaboyedoff (2012), Ambient seismic noise monitoring of a clay landslide: Toward failure prediction, J. Geophys. Res., 117, F01030, doi:10.1029/2011JF002159.
(2) Seismic data have been acquired by the French National Landslide Observatory (OMIV), and are available at doi.org/10.15778/RESIF.FR and doi.org/10.15778/RESIF.MT
How to cite: Wienk, I., Guillemot, A., Radiguet, M., Helmstetter, A., and Larose, E.: Decennial Monitoring of the Séchilienne Landslide with Seismic Noise, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8256, https://doi.org/10.5194/egusphere-egu25-8256, 2025.
