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Titel |
Multidisciplinary characterisation of sedimentary processes in a recent maar lake (Lake Pavin, French Massif Central) and implication for natural hazards |
VerfasserIn |
E. Chapron, P. Albéric, D. Jézéquel, W. Versteeg, J.-L. Bourdier, J. Sitbon |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1561-8633
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Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Science ; 10, no. 9 ; Nr. 10, no. 9 (2010-09-06), S.1815-1827 |
Datensatznummer |
250008394
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Publikation (Nr.) |
copernicus.org/nhess-10-1815-2010.pdf |
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Zusammenfassung |
Sedimentation processes occurring in the most recent maar lake of the French
Massif Central (Lake Pavin) are documented for the first time based on high
resolution seismic reflection and multibeam bathymetric surveys and by piston
coring and radiocarbon dating on a sediment depocentre developed on a narrow
sub aquatic plateau. This new data set confirms the mid Holocene age of maar
lake Pavin formation at 6970±60 yrs cal BP and highlights a wide range
of gravity reworking phenomena affecting the basin. In particular, a slump
deposit dated between AD 580–640 remoulded both mid-Holocene lacustrine
sediments, terrestrial plant debris and some volcanic material from the
northern crater inner walls. Between AD 1200 and AD 1300, a large slide
scar mapped at 50 m depth also affected the southern edge of the sub aquatic
plateau, suggesting that these gas-rich biogenic sediments (laminated
diatomite) are poorly stable. Although several triggering mechanisms can be
proposed for these prehistoric sub-aquatic mass wasting deposits in Lake
Pavin, we argue that such large remobilisation of gas-rich sediments may
affect the gas stability in deep waters of meromictic maar lakes. This study
highlights the need to further document mass wasting processes in maar lakes
and their impacts on the generation of waves, favouring the development of
dangerous (and potentially deadly) limnic eruptions. |
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