EGU23-6005, updated on 14 Jun 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

What are the causes of repeated mass-transport deposits in perialpine Lake Brienz (Switzerland)?

Stéphanie Girardclos1, Renaldo Gastineau2, Katrina Kremer2, and Flavio S. Anselmetti2
Stéphanie Girardclos et al.
  • 1University of Geneva, Department of Earth sciences and Institute of Environmental Sciences, Geneva, Switzerland (
  • 2University of Bern, Institute of Geological Sciences and Oeschger Centre for Climate Change Research, Bern, Switzerland (,,

Mass transport deposits (MTDs) are common features in lakes that impose a significant natural hazard as they can be tsunamigenic (e.g., in Lake Geneva; Kremer et al., 2012). MTDs can be assigned to different categories, such as lateral-slope landslides, margin collapses, delta collapses and rockfalls (Sammartini et al., 2019). In 1996 AD, a MTD occurred in Lake Brienz, a 260 m deep Alpine lake at the frontal range of the Bernese Swiss Alps. The 1996 MTD extends over ∼8.5 km2 and has a total volume of 2.7 106 m3, which amounts to ∼8.7 years of the lake’s annual sediment input. The 1996 MTD had no specific trigger and occurred as a spontaneous failure due to sediment accumulation on the Aare Delta (Girardclos et al., 2007).

However, the 1996 delta collapse was not a unique event: a dense grid of 240 km of seismic lines reveals at least four older massive MTDs in the lake basin with similar dimensions. Our study aims to identify the ages and the processes behind these large deposits. For this purpose, we focus on long sediment cores with a cumulative length of about 40 m from four coring locations. A combined analysis of seismic profiles and sediment cores, coupled with an age model combining radionuclides, radiocarbon, coal and steamboat slag, and historical flood events, allows us to explore the feedback between climate and anthropogenic impact acting upon these MTDs. The MTDs are analysed regarding their source areas, either the Aare or the Lütschine deltas, both occurring at the opposite ends of the elongated lake basin. Moreover, we investigate whether earthquakes, spontaneous failures or a shift of the Lütschine River could act as potential triggers, as well as the role of sediment loading in the deltas related to climate changes or anthropogenic impacts in the watershed. Altogether, these factors have likely affected the recurrence rates of these significant sedimentological events.



Girardclos, S., Schmidt, O.T., Sturm, M., Ariztegui, D., Pugin, A., Anselmetti, F.S., 2007. The 1996 AD delta collapse and large turbidite in Lake Brienz. Mar. Geol. 241, 137–154.

Kremer, K., Simpson, G., Girardclos, S., 2012. Giant Lake Geneva tsunami in AD 563. Nat. Geosci. 5, 756–757.

Sammartini, M., Moernaut, J., Anselmetti, F.S., Hilbe, M., Lindhorst, K., Praet, N., Strasser, M., 2019. An atlas of mass-transport deposits in lakes. Submar. Landslides Subaqueous Mass Transp. Depos. Outcrops Seism. Profiles 201–226. 

How to cite: Girardclos, S., Gastineau, R., Kremer, K., and Anselmetti, F. S.: What are the causes of repeated mass-transport deposits in perialpine Lake Brienz (Switzerland)?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6005,, 2023.