Accessing European strong-motion data: an update on ORFEUS Coordinated Services

Strong ground motion records and free open access to strong-motion data repositories are fundamental inputs to seismology, engineering seismology, soil dynamics, and earthquake engineering science and practice. This paper presents the current status and outlook of the ORFEUS (Observatories & Research Facilities for European Seismology) coordinated strong-motion seismology services, namely the Rapid Raw Strong Motion (RRSM) and the Engineering Strong Motion (ESM) databases and associated web interfaces and web services. We compare and discuss the role and use of these two systems using the Mw 6.5 Norcia (Central Italy) earthquake that occurred on October 30, 2016 as an example of a well-recorded earthquake that triggered major interest in the seismological and earthquake engineering communities. The RRSM is a fully automated system for rapid dissemination of earthquake shaking information, while the ESM provides quality-checked, manually processed waveforms and reviewed earthquake information. The RRSM uses only data from EIDA (the European Integrated Waveform Data Archive), while the ESM includes also offline data from other sources, such as the Italian strong-motion database ITACA. Advanced software tools are also included in the ESM to allow users to process strong-motion data and to select ground-motion waveform sets for seismic structural analyses. The RRSM and ESM are complementary services designed for a variety of possible stakeholders, ranging from scientists to the educated general public. The RRSM and ESM are developed, organized and reviewed by selected members of the seismological community in Europe, including strong-motion data providers and expert users. Global access and usage of the data is encouraged. The ESM is presently the reference database for harmonised seismic hazard and risk studies in Europe. ORFEUS strong-motion data are open, FAIR, and accompanied by licencing information. The users are encouraged to properly cite the data providers, preferably using seismic network DOIs (Digital Object Identifiers).