Journal
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
Volume 121, Issue 1, Pages 2-16Publisher
AMER GEOPHYSICAL UNION
DOI: 10.1002/2015JF003644
Keywords
lake sediment; sensitivity; historic earthquakes; paleoseismology
Categories
Funding
- French National Research Agency's Pygmalion project [ANR BLAN07-2_204489]
- AXA Research Fund (Wilhelm's postdoctoral fellowship)
- Conseil Regional de Franche-Comte
- University of Franche-Comte (OREAS project)
Ask authors/readers for more resources
Seismic hazard assessment is a critical but challenging issue for modern societies. A key parameter to be estimated is the recurrence interval of damaging earthquakes. This requires the establishment of earthquake records long enough to be relevant, i.e., far longer than historical observations. We study how lake sediments can be used for this purpose and explore conditions that enable lake sediments to record earthquakes. This was achieved (i) through the compilation of eight lake-sediment sequences from the European Alps to reconstruct chronicles of mass movement deposits and (ii) through the comparison of these chronicles with the well-documented earthquake history. This allowed 24 occurrences of mass movements to be identified, of which 21 were most probably triggered by an earthquake. However, the number of earthquake-induced deposits varies between lakes of a same region, suggesting variable thresholds of the lake sequences to record earthquake shaking. These thresholds have been quantified by linking the mass movement occurrences in a single lake to both intensity and distance of the triggering earthquakes. This method offers a quantitative approach to estimate locations and intensities of past earthquake epicenters. Finally, we explored which lake characteristics could explain the various sensitivities. Our results suggest that sedimentation rate should be larger than 0.5mmyr(-1) so that a given lake records earthquakes in moderately active seismotectonic regions. We also postulate that an increasing sedimentation rate may imply an increasing sensitivity to earthquake shaking. Hence, further paleoseismological studies should control carefully that no significant change in sedimentation rates occurs within a record, which could falsify the assessment of earthquake recurrence intervals.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available