extreme precipitations; Holocene; paleoclimatology; sublacustrine mass movement; human impact; flood; lake sediment; seismic stratigraphy; environmental change; turbidite; tsunami
Kremer Katrina, Corella Juan Pablo, Hilbe Michael, Marillier François, Dupuy David, Zenhäusern Gregor, Girardclos Stéphanie (2015), Changes in distal sedimentation regime of the Rhone delta system controlled by subaquatic channels (Lake Geneva, Switzerland/France), in Marine Geology
, 370, 125-135.
Kremer Katrina, Corella Juan Pablo, Adatte Thierry, Garnier Emmanuel, Zenhäusern Gregor, Girardclos Stéphanie (2015), Origin of turbidites in deep Lake Geneva (France–Switzerland) in the last 1500 years, in Journal of Sedimentary Research
, 85(12), 1455-1465.
Kremer Katrina, Hilbe Michael, Simpson Guy, Decrouy Laurent, Wildi Walter, Girardclos Stéphanie (2015), Reconstructing 4000 years of mass movement and tsunami history in a deep peri-Alpine lake (Lake Geneva, France-Switzerland), in Sedimentology
, 62(5), 1305-1327.
Thevenon F., Poté J., Girardclos S., Adatte T., de Alencastro L.F. (2014), Etude des sédiments lacustres. L'impact des activités humaines sur la qualité des ressources naturelles en eau., in Aqua & Gas
, 3, 22-31.
Kremer Katrina, Marillier François, Hilbe Michael, Simpson Guy, Dupuy David, Yrro BleJ.F., 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.
Ndiaye Matar, Clerc Nicolas, Gorin Georges, Girardclos Stephanie, Fiore Julien (2014), Lake Neuchatel (Switzerland) seismic stratigraphic record points to the simultaneous Wurmian deglaciation of the Rhone Glacier and Jura Ice Cap, in Quaternary Science Reviews
, 85, 1-19.
Wunderlin Tina, Corella Juan Pablo, Junier Thomas, Bueche Matthieu, Loizeau Jean Luc, Girardclos Stéphanie, Junier Pilar (2013), Endospore-forming bacteria as new proxies to assess impact of eutrophication in Lake Geneva (Switzerland-France), in Aquatic Sciences
, 76(S1), 103-116.
Thevenon Florian, Wirth Stefanie B., Fujak Marian, Pote John, Girardclos Stephanie (2013), Human impact on the transport of terrigenous and anthropogenic elements to peri-alpine lakes (Switzerland) over the last decades, in AQUATIC SCIENCES
, 75(3), 413-424.
Corella Juan Pablo, Arantegui Angel, Loizeau Jean Luc, Delsontro Tonya, Le Dantec N., Stark Nina, Anselmetti Flavio S., Girardclos Stéphanie (2013), Sediment dynamics in the subaquatic channel of the Rhone delta (Lake Geneva, France/Switzerland), in Aquatic Sciences
, 76(S1), 73-87.
From the mid-19th century, when the Northern Hemisphere climate ended a phase of cool temperatures (‘Little Ice Age’) and alpine glaciers started to retreat, most river systems in Switzerland were heavily modified by humans to artificially regulate lake-levels and river flows, with the aim to reduce flooding hazard. Overall, these infrastructures reached their goal but during the past two decades catastrophic floods occurred on a regular basis, bringing new questions on the frequency and magnitude of these events, as well as their related sedimentary processes. Lake sediments are genuine archives of human- or climate-induced environmental changes at local and regional scale. The study of lacustrine records allows the detailed reconstruction of these past changes and events.The initial phase of this research project in Lake Geneva revealed numerous large turbidites and mass movement deposits in its deepest basin. The youngest event layer, a co-genetic debrite-turbidite, is dated to the collapse of the Rhône delta due to the Tauredunum rockfall in 563 AD and generated a tsunami wave with 8 m high wave reaching Geneva in 70-80 minutes, as shown by numerical simulations and historical records (Kremer et al., 2012). In Lake Biel, the recent sediment record (1850-2010) didn’t record floods as specific clastic clayers. Instead, it revealed the history of human impact on natural and anthropogenic trace element fluxes in the Aare river catchment, with highest lead enrichment factors due to pollution happening between 1940 and 1970. The comparison of the natural lithogenic element flux with precipitation data suggests that sediment-trapping reservoirs significantly disrupted regional fluvial sediment supply (Thevenon et al., in press).In this proposal (phase 2), we plan to analyze the remaining ‘non mass movement-related’ sediment record of Lake Geneva to recognize flood layers from background hemi-pelagic sediment record and to identify sediment sources. The frequency and sedimentary characteristics of these beds will be linked to historical large flood events. Recent data will also be interpreted using available instrumental meteorological and hydrological records. Special attention will be given to comparison of flood deposit record before and after the regional Rhône river management was put in place, which will reveal how human-made modifications changed the river and lacustrine systems. In Lake Biel, we plan to complete the on-going research on (7000 years old) retrieved sediment sequence to reconstruct the longer-term past climatic and environmental changes of the Seeland region. The distinct human impact history of Lake Geneva and Lake Biel catchments, as well as their contrasted position (proximal vs. distal) in peri-alpine river systems, offers an excellent opportunity to compare and understand clastic sedimentology processes from similar climate and matching time scales.