The key duties of Institute of Seismology includes registration and analysis of seismic events in Finland and northern Europe. A seismic event can be a natural earthquake, or a human-induced event such as an explosion or an induced earthquake. The institute registers earthquakes not only in the nearby areas but also from larger distances on the globe. The analysis of seismic events includes classification, and determination of the location, magnitude, and depth of the event. For the research of Finnish and northern European events, the institute uses data from observation stations in Finland and also from other neighbouring areas.
Tens of Finnish earthquakes are registered yearly. These earthquakes are relatively weak, with magnitudes 0...4. As the network is being densified, smaller earthquakes can be registered and the number of located earthquakes increases.
Have you observed a Finnish earthquakes or been in the area of perceptibility of a Finnish earthquake? You can help us by filling a macroseismic questionnaire. You may fill it even if you are not sure whether the event you observed was an earthquake. Institute of Seismology reviews all observations and announces Finnish earthquakes at its website within approximately three business days.
The institute gathers information on how broad is the area and in what ways are different-sized earthquakes observed or sensed. The aim is that after an earthquake, as many persons as possible fill the questionnaire.
Observations are gathered for non-commercial purposes. Information is not delivered to any third party.
Energy accumulated in the bedrock is released in an earthquake. It is spread to different directions as seismic waves. In a strong earthquake, plenty of energy is released, and the resulting seismic waves reach long distances before they eventually attenuate. A small event triggers less ample waves.
Seismic waves are registered by seismometers. Their distances to the epicentre vary and due to that waves travel different distances to measurement locations. The epicenter can be localized using time differences. People can also notice seismic waves as they pass way. A person outdoors can observe tremor in soil, while a person indoors can observe how tremor affects furniture and other household staff. Observations are always subjective and limited to certain location, but if their number is sufficient, they are helpful in getting a general view on the earthquake and its effects.
Familiarize yourself with earthquakes as a phenomenon and a seismological glossary (in Finnish).