Premium
Reconstructing historical seismicity from lake sediments (Lake Laffrey, Western Alps, France)
Author(s) -
Nomade Jérôme,
Chapron Emmanuel,
Desmet Marc,
Reyss JeanLouis,
Arnaud Fabien,
Lignier Vincent
Publication year - 2005
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2005.00620.x
Subject(s) - geology , debris flow , landslide , debris , slope failure , structural basin , sediment , induced seismicity , geomorphology , physical geography , hydrology (agriculture) , geochemistry , archaeology , seismology , oceanography , geotechnical engineering , geography
Sediment archives from a mountain lake are used as indicators of seismotectonic activity in the Grenoble area (French western Alps, 45°N). Sedimentological analysis (texture and grain‐size characteristics) exhibits several layers resulting from instantaneous deposits in Lake Laffrey: six debris flow events up to 8 cm thick can be attributed to slope failure along the western flank of the basin. Dating with 210 Pb and 137 Cs gamma counting techniques and the reconnaissance of historical events, provide a constrained age‐depth model. Over the last 250 years, five of such debris flow deposits could be related to historical earthquakes of MSK intensities greater than VI over an area of <60 km. One debris flow deposit triggered at the beginning of the last century can be related to an historical landslide possibly triggered by the artificial regulation of the lake level.