Year: 2024
Type: article
Abstract: In the Mediterranean Sea, the probability that a large earthquake-triggered tsunami will occur in the coming decades is high. Historical tsunami database informs us on their geographical occurrence but their sources, i.e., the faults that slipped during earthquakes and displaced the seafloor to generate tsunamis, are often unknown. Here we identify the submarine rupture of the Amorgos earthquake that on July 9, 1956, triggered the largest mediterranean tsunami in the past two centuries. Using submarines, we explored major normal faults in the epicentral area, and discovered a large surface rupture along the 75-km long Amorgos fault. The 9.8-16.8-m large seafloor offset is compatible with a Mw7.5 event. This finding prompts a reassessment of the largest (≥20 m) tsunami wave origin, previously attributed to earthquake-triggered submarine mass-wasting. It demonstrates that tsunami source can be determined several decades after an event, a key information to better assess future seismic and tsunami hazards. A surface rupture which offset the seabed by 9.8-16.8 m along the 75 km long Amorgos fault is probably the main cause of the largest tsunami in the Mediterranean Sea in the last two centuries, according to direct submarine observations.
Institutions: Centre National de la Recherche Scientifique, Université Côte d'Azur, Observatoire de la Côte d’Azur, Géoazur, Institut de Recherche pour le Développement, Institut de physique du globe de Paris, Université Paris Cité, National and Kapodistrian University of Athens, Universitat de Girona, Université Paris Sciences et Lettres, École Normale Supérieure - PSL, Laboratoire de Géologie de l’École Normale Supérieure
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,290
OpenAlex ID: W4404111956