The Seismological Service at GeoSphere Austria is the principal authority for earthquakes in Austria. As such, it is responsible for informing the population, relevant authorities, and disaster relief services about relevant earthquakes, operating the national seismic monitoring network, documenting the impact of earthquakes, and determining the earthquake hazard.
Past earthquakes have caused severe damages to buildings and loss of life in Austria, justifying the need for adequate protective measures. Even though earthquakes belong to the non-forecastable natural phenomena, it is possible to protect oneself from their effects through earthquake-resistant construction and correct behaviour during an earthquake. Targeted prevention and effective crisis management after an earthquake can further limit damage and even save lives.
Rapid
Information for Disaster Relief Services and the Population
If an earthquake, felt by the population in Austria, is registered by the seismological monitoring network, the Seismological Service at GeoSphere Austria informs the state crisis management as well as the public and media about the recent earthquake and its expected impact. Through international data exchange, the Austrian network is enhanced with seismic stations from other countries. In total, registrations from over a hundred seismic stations are processed in real time. Strong earthquakes worldwide are also assessed and the Seismological Service advises the state crisis management on the effects on Austrian territory or Austrian citizens who are in the earthquake zone.
The ground motion at the seismological stations is monitored around the clock, and in the event of a strong earthquake, an alarm is sent to the seismologist on duty. The event is immediately analysed by a seismologist. This analysis includes determining the strength (magnitude), location and depth of the earthquake as well as characterizing and describing the expected impact. Based on measurements of the ground motion as well as earthquake reports submitted by the public, the situation is rapidly assessed. A seismologist is always on stand-by to advice state crisis and disaster management.
The Austrian Seismological Service participates in the national multi-hazard platform AMAS and also advises the European Union’s Emergency Response Coordination Centre (ERCC) in the event of catastrophic earthquakes worldwide as part of the European ARISTOTLE project.
How are seismic data analysed?
The analysis of an earthquake includes the analysis of the seismograms from each individual station, the determination of the onsets on each of the three components of the sensor (vertical, North and East component) and the picking of the initial onsets and subsequent phases. This is followed by an event interpretation to determine the event type. In the case of stronger earthquakes, the focal mechanism is analysed as well. The seismic network records not only earthquakes and mining blasts, but also signals from explosions or nuclear weapon tests, sonic booms, rockfalls, and even signals from concerts.
Can earthquakes be predicted?
The current state of research does not permit the prediction of the time, location, or magnitude of an earthquake. Seismic unrest may precede a major earthquake, but is not a reliable precursor. Conspicuous animal behaviour or other phenomena in nature are also not indicators of the imminent occurrence of an earthquake. It is, however, possible to use hazard analysis to estimate the statistical probability of an earthquake of a certain magnitude occurring in a specific area.
What are earthquake early warning systems?
Early warning systems offer the possibility of reacting quickly and efficiently to a strong earthquake that is currently occurring. They are used in countries with a very high earthquake risk (e.g. Japan, USA and Turkey). The information that a major earthquake has occurred is available within a very short time after automatic localization or registration of the (rapidly propagating) primary wave, even before the arrival of the dangerous (more slowly propagating) surface waves in the endangered area. Depending on the distance to the epicentre, there is still time to warn the population, shut down sensitive facilities, stop trains and other means of transport and close bridges. This way, potentially disastrous consequences can be prevented.
What is a ShakeMap?
A ShakeMap provides rapid information about the ground motion caused by an earthquake and the impact felt by the population. It estimates which areas are most affected and whether damage is to be expected. The map is generated and regularly updated based on measurements from seismic stations and the automatically classified felt reports from the population immediately after the earthquake.
Earthquakes in Austria: Facts and Figures
In Austria, the population feels an average of 70 earthquakes every year. The majority of these are noticeable only through a distinctive rattling. Minor damage to buildings occurs on average every two to three years. Strong earthquakes that cause severe damage to buildings are also possible in Austria. However, these rare events only take place approximately every 100 years.
In general, earthquakes can occur almost anywhere in Austria. However, areas with the most earthquakes are located in zones with higher tectonic activity. These include the Rhine Valley in Vorarlberg, the Inn Valley and its branch valleys, the Mur and Mürztal valleys, the Semmering area, and the Vienna Basin.
What is the cause of earthquakes in Austria?
Earthquakes occur when stress in the subsurface, which built up due to the movement of tectonic plates, are suddenly released. This release of stress happens not only at the plate boundary, but also on geological fault zones inside the plates. In Europe, the tectonic stress field is determined by the Adriatic Plate, which is drifting northwards and colliding with the Eurasian Plate. One consequence of this collision is the formation of the Alps, which is connected to earthquake activity.
What were the strongest known damaging earthquakes in Austria?
15/09/1590 – Two earthquakes near Ried am Riederberg/Lower Austria with intensities VIII and IX.
17/07/1670 – Earthquake near Hall in Tyrol with intensity VIII.
04/12/1690 – Earthquake north of Villach/Carinthia with intensity VIII.
08/10/1927 – Earthquake near Schwadorf/Lower Austria with intensity VIII.
The impact of these earthquakes could be assessed and documented through historical earthquake research. Less well documented are two other events near Katschberg/Carinthia (1201) and Kindberg/Styria (1267) with similar intensity values.
How high were the maximum magnitudes in Austria?
Five moderate to strong earthquakes are well documented. The magnitudes of historical earthquakes before 1900 were reconstructed using intensity models.
04.12.1690 – Earthquake north of Villach/Carinthia, magnitude 6.4.
15.09.1590 – Earthquake near Ried am Riederberg/Lower Austria, magnitude 5.8.
07.10.1930 – Earthquake near Namlos/Tyrol, magnitude 5.3.
27.10.1964 – Earthquake at Semmering/Lower Austria, magnitude 5.3.
16.04.1972 – Earthquake near Seebenstein/Lower Austria, magnitude 5.3.
Less well documented are the earthquakes near Katschberg/Carinthia (1201) and Kindberg/Styria (1267) with similar magnitudes.
Emergency Preparedness
GeoSphere Austria not only provides rapid information after an earthquake. By developing earthquake scenarios, our seismologists also support disaster response exercises organised by the federal states and the EU civil protection and disaster control. These civil protection exercises ensure that necessary steps can be carried out quickly and efficiently in the case of an emergency. A theoretically possible earthquake is defined for the region including impacts such as damage to buildings, cracks in the soil, or disruption to traffic or energy supply lines. These earthquake scenarios form the basis for the training exercise. Seminars are also offered for organizations involved in disaster control, such as the Red Cross or the European Emergency Response Coordination Centre (ERCC).
Evaluating Earthquake Hazard to Prevent Damage
GeoSphere Austria also contributes to public safety by providing information on the local earthquake hazard. While earthquakes can occur almost anywhere in Austria, some regions are more affected than others are. Knowledge of tectonics, geology, and earthquake history is used to estimate the average frequency and magnitude of earthquakes. Based on these data, buildings in earthquake-prone areas can be constructed or reinforced to be able to withstand the expected level of ground motion. To ensure sustainable earthquake prevention, GeoSphere Austria provides the basic data for the development of guidelines and for the planning of earthquake-resistant buildings.
Data from various sources and an earthquake catalogue that reaches as far back into the past as possible are highly important for research and development in the field of earthquake hazard. Everything from the results of historical earthquake research through to instrumental registrations of recent earthquakes are factored in. The impact of earthquakes, such as damage to buildings, is recorded and documented through reports from the population and through on-site inspections around the epicentre. Historical seismograms from 1904 onwards, after being digitized from the archive, are also heavily utilized.
We provide our expertise for studies and large construction projects by determining the design loads and estimating the potential earthquake intensity. In order to determine whether a site amplifies or dampens earthquake waves, measurements can be carried out on-site and data from past earthquakes can be used for modelling.
Why are historical earthquakes still relevant today?
Austria has moderate seismicity, however, strong earthquakes that cause severe damage to buildings are possible. Historically, they occurred on average every 100 years or even less frequently. Therefore, precise knowledge of historical earthquakes, especially damaging ones, from the period for which no instrumental measurements are available, is of great importance. Since the introduction of EUROCODE-8, the seismic code for earthquake-resistant construction in Europe, in the year 2009 the recording and source-critical assessment of historical earthquakes has become essential, as the period for which the earthquake hazard must be determined has been extended from 100 to over 450 years. This change has a massive impact on the construction and real estate industry as well as the policies involved, and hence enormous economic significance.
What is an earthquake catalogue?
The Austrian Earthquake Catalogue (AEC) is the basis for the current, state-of-the-art Austrian earthquake hazard map. This fundamental database allows for the development of guidelines, which are used in the planning of earthquake-proof buildings (e.g. ÖNORM EN-1998-1). The AEC forms the basis for all further research and thus ensures targeted damage prevention. It contains data on earthquakes from various sources: historical earthquake research, instrumental recordings from the earthquake monitoring network and the felt reports from the population. The Seismological Service at GeoSphere Austria is the central office for documenting the impacts of earthquakes since 1904.
Seismic monitoring: from infrastructure to nuclear weapons tests
GeoSphere Austria monitors local infrastructure in order to document the intensity of earthquake shaking and to inform clients immediately if pre-defined threshold values are exceeded. Examples include the monitoring and discrimination of natural seismicity from the induced seismicity that can occur in mining or deep geothermal energy. The tasks include the planning, construction and operation of local networks, as well as the integration into the national strong-motion network.
Austria’s capital Vienna is home to another, separate, strong-motion monitoring network. In connection with Austria's commitment to the Comprehensive Test Ban Treaty (CTBT), the National Data Centre, which is responsible for the continuous monitoring of potential nuclear weapons tests, is located at GeoSphere Austria.
