The magnitude is a logarithmic measure of the vibration energy released at the seismic focus. It is determined from the recorded seismograms and is available immediately after localization. The intensity describes the effects of the earthquake on the earth's surface and is determined using earthquake reports from the population and damage information. The assessment is carried out according to the 12-level European Macroseismic Scale (EMS-98). Based on models, it is possible to estimate the effects of an earthquake at a specific location – the local intensity – from the magnitude and focal depth of an earthquake.
Reporting Earthquakes
Support the seismological service and the emergency service with your earthquake report. Despite our modern seismic network, your reports of what you observed are essential.
The close-meshed seismic network enables precise localization and magnitude determination of an earthquake. However, depending on the soil condition and the underground structures, the local effects of an earthquake, such as damage to buildings, can vary considerably. In order to know to what extent an earthquake has affected the population, infrastructure and nature, we rely on your earthquake reports.
Therefore, we kindly ask you to report your observations after you have felt an earthquake. You can use either the web form or our QuakeWatch Austria app to report your earthquake:
Since 1904, the seismological service has documented the effects of earthquakes by collecting observations from the population. During the last 20 years, we have received more than 150,000 questionnaires, which we evaluated manually and automatically. The macroseismic intensity is determined based on these reports. It is a decisive measure of the perceived strength of vibration on the earth's surface and the probability of damage to buildings.
The macroseismic intensity describes the strength of the shaking caused by an earthquake at a specific location. The intensity can be classified using the 12-level European Macroseismic Scale (EMS-98). Slight tremors are rated as Grade II or III, while clearly felt earthquakes are rated as Grade IV. At Grade V, some cracks in the plaster occur in a few cases, and building damage happens above Grade VI.
By submitting your report, you help the seismological service to quickly evaluate the local impacts of an earthquake. This information is not only of interest to the public, but is also provided directly to the state crisis and disaster management (SKKM). After an earthquake, emergency services can immediately access the estimated damage scenario and plan operations accordingly.
The results of the macroseismic assessment of the reports also serve as the basis for hazard studies, expert reports and the earthquake hazard map for Austria. This map shows where, statistically, what earthquake strengths and impacts can be expected. This information is incorporated into the building standards for earthquake-resistant construction. The evaluation of local amplification effects and relationships between intensity and ground vibration velocity or acceleration are other important applications. Insurance companies also use the local intensity when evaluating damage reports.
The team of the seismological service is available for inquiries and information at seismo@geosphere.at.