DETECT: seismological data from multiple dense arrays deployed across the Irpinia fault system in southern Italy

We present a large seismological dataset (https://geofon.gfz.de/doi/network/ZK/2021) composed by continuous recordings from 200 temporary stations (seismic network ZK, 10.14470/MX7576871994), which operated continuously for approximately one year in the Southern Apennines (Southern Italy) as part of the DETECT experiment. The dataset is compliant with the seismological standards for the archiving of data and metadata, and with standardized tools for disseminating them, e.g., the International Federation of Digital Seismograph Networks (FDSN) web services. The data set was collected during the DETECT experiment in the Irpinia area (southern Italy), which is one of the regions with the highest seismic hazard in Italy. From August 2021 to August 2022, a constellation of 20 seismic arrays, with a total of 200 seismic stations, was installed above the fault segments responsible for the M 6.9, 1980 Irpinia earthquake, the strongest and most destructive seismic event in Italy in the last fifty years. Each seismic array had a maximum aperture of ~2 km and was composed of one broad-band sensor, one short- period sensor with 1 Hz and eight 4.5 Hz natural frequency geophones. Data and metadata were managed in accordance with the GIPP/GEOFON policy using SeisComP (Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences and GEMPA GmbH, 2008) and the final archive size is approximately 5.2 TB. In this contribution, we provide details on how to download waveform data and station metadata, as well as information on data availability and quality.