Skip to main content
U.S. flag

An official website of the United States government

Lakes as paleoseismic records in a seismically-active, low-relief area (Rieti Basin, central Italy)

March 29, 2019

Small lakes in low relief areas are atypical candidates for studies on paleoseismicity, but their sediments can contain seismically induced event layers (seismites) generated through strong ground shaking, sediment transport, hydrological reorganization and/or changes in groundwater chemistry and flow. Lakes Lungo and Ripasottile are shallow lakes (<10m deep) located in the tectonically active Rieti Basin in the central Apennines, Italy, where strong normal faulting earthquakes (Mw 6.5 to 7.0) regularly occur. Sediment cores from these lakes provide paleoseismic indicators for the past ~1000 years. Sedimentological and geochemical analysis reveals four event layers identified in both lakes that correspond with documented large-scale earthquakes in 1298, 1349, 1639, and 1703 AD. Chronological correlation between earthquakes and possible seismites is reliable because of the unusually high resolution of sediment dating available for the studied cores. The common physical structure is a physically homogenous bed (homogenite) of re-suspended sediment consisting of a denser, high magnetic susceptibility (MS) clastic base, with organic matter concentrated above. Chemical signatures are associated with some event layers and may represent abrupt or transient shifts to a groundwater-dominated system, or permanent changes in groundwater flow and/or spring discharge. Excursions in δ13Corg may represent disruptions or changes in carbon source. Not all event layers show the same features, a result attributed to differences in seismic processes as well as the lake attributes, and anthropogenic modification. The observations made here may provide a new means of detecting paleoseismicity and may be applied to other low relief lakes in seismically active areas.

Citation Information

Publication Year 2019
Title Lakes as paleoseismic records in a seismically-active, low-relief area (Rieti Basin, central Italy)
DOI 10.1016/j.quascirev.2019.03.004
Authors Claire Archer, Paula Noble, Michael R. Rosen, Leonardo Sagnotti, Fabio Fiorindo, Gianluca Piovesan, Scott Mensing, Alessandro Michetti
Publication Type Article
Publication Subtype Journal Article
Series Title Quaternary Science Reviews
Series Number
Index ID 70202853
Record Source USGS Publications Warehouse
USGS Organization WMA - Earth System Processes Division

Related Content