Helsingin seisminen asemaverkko ja seismisyys 2023

HelsinkiNet, the collaborative seismological observation network of the Institute of Seismology and the City of Helsinki, turned three full operational years at the end of 2023. As in the previous year, stations KUNI, LAUT, RSUO and VUOS functioned in the network as a part of the national automatic detection system. In the capital region, stations HEL1, HEL2, and HEL3 built for monitoring the geothermal plant project of St1 Inc. supplemented their observations. During the year, the daily analysis of the institute handled 369 seismic events that occurred at a maximum distance of 30 km
from the Central Railway Square of Helsinki. They included one natural earthquake in the outer archipelago of Helsinki, one south of Porkkala, Kirkkonummi, and one in Nikkilä, Sipoo. A more detailed analysis based on a cross correlator also probably revealed two very small earthquakes from the sea area of Helsinki, yet without accurate location or magnitude information. The institute received citizen observations about earthquakes only from the event of Sipoo. No induced earthquakes were observed.