The European Fault-Source Model 2020 (EFSM20): geologic input data for the European Seismic Hazard Model 2020

Abstract. Earthquake hazard analyses rely on the availability of seismogenic source models. These are designed in different fashions, such as point sources or area sources, but the most effective is the three-dimensional representation of geological faults. We here refer to such models as fault sources. This study presents the European Fault-Source Model 2020 (EFSM20), which formed the basis for one of the primary input datasets of the recently released European Seismic Hazard Model 2020. The EFSM20 compilation was entirely based on reusable data from existing active fault regional compilations that were first blended and harmonized and then augmented by a set of derived parameters. These additional parameters were devised to enable users to formulate earthquake rate forecasts based on a seismic-moment balancing approach. EFSM20 considers two main categories of seismogenic faults: crustal faults and subduction systems. The compiled dataset covers an area from the Mid-Atlantic Ridge to the Caucasus and from northern Africa to Iceland. It includes 1,248 crustal faults spanning a total length of ~95,100 km and four subduction systems, namely the Gibraltar, Calabrian, Hellenic, and Cyprus Arcs. The model focuses on an area encompassing a buffer of 300 km around all European countries (except for Overseas Countries and Territories, OTCs) and a maximum of 300 km depth for the subducting slabs. All the parameters required to develop a seismic source model for earthquake hazard analysis were determined for crustal faults and subduction systems. A statistical distribution of relevant seismotectonic parameters, such as faulting mechanisms, slip rates, moment rates, and prospective maximum magnitudes, is presented and discussed to address unsettled points in view of future updates and improvements. The dataset, identified by the DOI https://doi.org/10.13127/efsm20, is distributed as machine-readable files using open standards (Open Geospatial Consortium).