In 2019–2020, the Institute of Seismology set up, in collaboration with the City of Helsinki, a seismic network, HelsinkiNet, consisting of three stations. The stations of the network were in operation in Kuninkaantammi (KUNI), Lauttasaari (LAUT), and Vuosaari (VUOS) in association with the automatic observation systems of Finland and the Helsinki region. The noise level of stations was low considering their locations, and no long interruptions to data delivery have taken place. In addition to HelsinkiNet, stations HEL1-HEL5 established for the monitoring of the St1 deep heat project were operational in the western part of Helsinki region. In 2020, the number of confirmed seismic events within 30 km from the Central Railway Station of Helsinki was 484, most of them explosions. Induced earthquakes happened in Espoo, particularly in Otaniemi, but also in Koskelo. Three natural earthquakes occurred, two of them were 0.7-magnitude events in Vantaa and one was a –0.5-magnitude event in Laajaranta. The number of natural and induced earthquakes of at least magnitude 0.0 was 24. Most of the macroseismic observations of earthquakes were associated with the St1 geothermal plant project in Otaniemi, Espoo.
|Publisher||University of Helsinki, Institute of Seismology|