UNDERCOVER large-N Array Finland

This seismic network consisted of 493 geophone stations, with Geospace GS-One 5 Hz geophone sensors and Geospace GSB dataloggers, that recorded at 250 Hz from early June to early August 2025. There was an exchange of dataloggers and some re-deployment of stations at mid-term. The stations were deployed in northeastern Finland, close to the town of Ruka, in the framework of the Horizon Project UNDERCOVER, in an area of about 30x25 km. Together with a larger-scale broadband deployment that was carried out at the same time, the data were collected to illuminate the crustal structure of a major Paleoproterozoic shear zone, the Kuusamo Schist Belt. Waveform data is available from the GEOFON data centre, under network code 4J.