SI-Hex: a new catalogue of instrumental seismicity for metropolitan France

Abstract. – The aim of the SI-Hex project (acronym for « Sismicité Instrumentale de l’Hexagone ») is to provide a cata-logue of seismicity for metropolitan France and the French marine economic zone for the period 1962-2009 by taking into account the contributions of the various seismological networks and observatories from France and its neighbouring coun-tries. The project has been launched jointly by the Bureau Central Sismologique Français (CNRS-University/BCSF) and the Laboratoire de Détection et de Géophysique (CEA-DAM/LDG). One of the main motivations of the project is to pro-vide the end user with the best possible information on location and magnitude of each earthquake. So far, due to the vari-ous procedures in use in the observatories, the different locations and magnitudes of earthquakes located in the SI-Hex zone were presenting large discrepancies. In the 2014 version of the catalogue, 1D localizations of hypocentres performed with a unique computational scheme and covering the whole 1962-2009 period constitute the backbone of the catalogue (SI-Hex solutions). When available, they are replaced by more precise localizations made at LDG or, for recent times, by the regional observatories within: 1) the French Alps, 2) the southernmost Alps and the Mediterranean domain including Corsica, 3) the Pyrenees, and 4) the Armorican massif. Moment magnitudes Mw are systematically reported in the SI-Hex catalogue. They are computed from coda-wave analysis of the LDG records for most Mw>3.4 events, and are converte