6-kyr record of flood frequency and intensity in the western Mediterranean Alps - Interplay of solar and temperature forcing
Articolo
Data di Pubblicazione:
2017
Citazione:
6-kyr record of flood frequency and intensity in the western Mediterranean Alps - Interplay of solar and temperature forcing / P. Sabatier, B. Wilhelm, G.F. Ficetola, F. Moiroux, J. Poulenard, A.L. Develle, A. Bichet, W. Chen, C. Pignol, J.L. Reyss, L. Gielly, M. Bajard, Y. Perrette, E. Malet, P. Taberlet, F. Arnaud. - In: QUATERNARY SCIENCE REVIEWS. - ISSN 0277-3791. - 171(2017 Aug 15), pp. 121-135.
Abstract:
The high-resolution sedimentological and geochemical analysis of a sediment sequence from Lake Savine
(Western Mediterranean Alps, France) led to the identification of 220 event layers for the last 6000 years.
200 were triggered by flood events and 20 by underwater mass movements possibly related to earthquakes
that occurred in 5 clusters of increase seismicity. Because human activity could influence the
flood chronicle, the presence of pastures was reconstructed through ancient DNA, which suggested that
the flood chronicle was mainly driven by hydroclimate variability. Weather reanalysis of historical floods
allow to identify that mesoscale precipitation events called “East Return” events were the main triggers
of floods recorded in Lake Savine. The first part of this palaeoflood record (6e4 kyr BP) was characterized
by increases in flood frequency and intensity in phase with Northern Alpine palaeoflood records. By
contrast, the second part of the record (i.e., since 4 kyr BP) was phased with Southern Alpine palaeoflood
records. These results suggest a palaeohydrological transition at approximately 4 kyr BP, as has been
previously described for the Mediterranean region. This may have resulted in a change of flood-prone
hydro-meteorological processes, i.e., in the balance between occurrence and intensity of local convective
climatic phenomena and their influence on Mediterranean mesoscale precipitation events in this
part of the Alps. At a centennial timescale, increases in flood frequency and intensity corresponded to
periods of solar minima, affecting climate through atmospheric changes in the Euro-Atlantic sector.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Holocene; paleoclimatology; Western mediterranean alps; sedimentology; flood frequency and intensity; lake sediment; human activity; ancient DNA; earthquakes
Elenco autori:
P. Sabatier, B. Wilhelm, G.F. Ficetola, F. Moiroux, J. Poulenard, A.L. Develle, A. Bichet, W. Chen, C. Pignol, J.L. Reyss, L. Gielly, M. Bajard, Y. Perrette, E. Malet, P. Taberlet, F. Arnaud
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