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Holocene turbidites record earthquake supercycles at a slow-rate plate boundary

Gueorgui Ratzov, Antonio Cattaneo, Nathalie Babonneau, Jacques Deverchere, Karim Yelles, Rabah Bracene and Francoise Courboulex
Holocene turbidites record earthquake supercycles at a slow-rate plate boundary
Geology (Boulder) (April 2015) 43 (4): 331-334


Ongoing evidence for earthquake clustering calls for records of numerous earthquake cycles to improve seismic hazard assessment, especially where recurrence times overstep historical records. We show that most turbidites emplaced at the Africa-Eurasia plate boundary off west Algeria over the past approximately 8 k.y. correlate across sites fed by independent sedimentary sources, requiring a regional trigger. Correlation with paleoseismic data inland and ground motion predictions support that M approximately 7 earthquakes have triggered the turbidites. The bimodal distribution of paleo-events supports the concepts of earthquake supercycles and rupture synchronization between nearby faults: 13 paleo-earthquakes underpin clusters of 3-6 events with recurrence intervals of approximately 300-600 yr, separated by periods of quiescence of approximately 1.6 k.y. without major events on other faults over the study area. This implies broad phases of strain loading alternating with phases of strain release. Our results suggest that fault slip rates are time dependent and call for revising conventional seismic hazard models.

ISSN: 0091-7613
EISSN: 1943-2682
Serial Title: Geology (Boulder)
Serial Volume: 43
Serial Issue: 4
Title: Holocene turbidites record earthquake supercycles at a slow-rate plate boundary
Affiliation: Universite de Brest, Plouzane, France
Pages: 331-334
Published: 201504
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 25
Accession Number: 2015-054481
Categories: Quaternary geology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. geol. sketch map
N19°00'00" - N37°00'00", W09°00'00" - E12°00'00"
N35°10'00" - N44°30'00", W05°30'00" - E16°15'00"
Secondary Affiliation: Institut Francais de Recherche pour l'Exploitation de la Mer, FRA, FranceCentre de Recherche en Astronomie Astrophysique et Geophysique, DZA, AlgeriaSONATRACH Exploration, DZA, AlgeriaUniversite de Nice/Sophia-Antipolis, FRA, France
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 201525
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