Felt observations are of interest to researchers
In an earthquake, energy accumulated in bedrock is suddenly released. It spreads out from the hypocenter and propagates as seismic waves. Major earthquakes release a lot of energy, and its waves propagate over large distances before attenuating for good. A small seismic event excites weaker waves.
Seismic waves are registered with seismometers. Their distances along arc to the epicenter vary, meaning that the waves arrive at different stations at different times. With these time differences, it is possible to locate the hypicenter. People can also sense the seismic waves as they pass close. Outdoors you may feel the ground shaking and indoors you may observe how the vibration affects personal property. The locations are however always pertaining to one site and are thus subjective. If there are enough observation sites, however, it is possible to get an overall impression about the earthquake and its effects.
Have you observed an earthquake in Finland?
Have you observed an earthquake in Finland or been in its area of influence? You can help us by filling a microseismic questionnaire. You can also fill in the questionnaire even if you weren't sure if the event was an earthquake. The Institute of Seismology at University of Helsinki verifies all observations and announces recent earthquakes in Finland within three working days.
ISUH collects observations about the felt areas and effects of different-sized earthquakes. The objective is that after an earthquake, as many people as possible fill in the felt questionnaire. You can fill in the form even if you didn't observe anything – that is a useful piece of information as well.
The observations are collected for non-commercial purposes. The personal data collected with the questionnaire are not forwarded outside the institute.
You can fill in the felt questionnaire here.