Swiss Seismological Service
The Swiss Seismological Service (SED) at ETH Zurich is the federal agency for earthquakes . On his behalf, he monitors earthquake activity in Switzerland and in other countries near the border and assesses the earthquake hazard in Switzerland. In the event of an earthquake, the SED informs the public, authorities and the media about the location, the strength and possible effects. The activities of the SED are integrated into the federal program of measures to prevent earthquakes. He also conducts research and teaching and is responsible for Swiss participation in international nuclear test ban surveillance.
history
The beginnings of the Swiss Seismological Service go back to the establishment of the Earthquake Commission in 1878. In 1911 the first permanent earthquake control station in Switzerland was built in Degenried above Zurich. Three years later (1914) the mandate for earthquake monitoring was enshrined in federal law and a previously voluntary task was transferred to an institution. The SED has existed in its current form as an extra-departmental unit at ETH Zurich since 2009.
Earthquake monitoring
More than 200 seismic stations operated by the Swiss Seismic Service monitor earthquake activity in Switzerland and its neighboring countries in real time. These stations are spread across the country and installed in various locations, including caves, tunnels and even boreholes.
Switzerland needs a seismic network to monitor background seismicity and understand the consequences of rare, large earthquakes that cause considerable damage. This is also important in a country with a moderate earthquake risk such as Switzerland. A dense, state-of-the-art network that monitors earthquake activity in real time performs this task and quickly informs authorities, the media and the public about earthquakes resulting from significant seismic events. It also provides high quality data for risk studies and basic earthquake research.
Switzerland's dense seismic network consists of highly developed, modern and low-noise stations with real-time data transmission to distributed data processing centers at ETH Zurich . The data is analyzed and events are measured within a few seconds of their occurrence.
The seismic data come from the following sources:
- The national network of Switzerland (CHNet), consisting of the broadband network (SDSNet) and the strong earthquake network (SSMNet), mainly uses broadband seismometers to register weak local, moderate regional and moderate to strong global earthquakes. Accelerometers are used to register moderate and strong local earthquakes.
- Special (often temporary) networks are used to monitor increased natural earthquake activity, for example to measure aftershocks or to support research and training projects (such as AlpArray and seismo @ school). They are also used to monitor induced earthquakes as a result of geothermal projects or to carry out other commercial orders from third parties.
The exact localization of earthquakes depends on observations made by numerous stations without large azimuth distances, including stations close to the epicenter. However, since damaging earthquakes that occur in Switzerland can also have their origin in events beyond the country's borders, the seismic network also monitors all nearby, operating real-time stations in neighboring countries.
Earthquake hazard in Switzerland
Compared to other European countries, Switzerland has a medium earthquake hazard, although there are regional differences: More earthquakes are registered in Valais, Basel, St. Gallen Rhine Valley, Central Grisons, Engadine and Central Switzerland than in other areas. Earthquakes can occur anytime and anywhere in Switzerland.
The number of registered earthquakes in Switzerland is around 1,000 to 1,500 per year. An average of 10 to 20 earthquakes are strong enough to be felt by the population. A strong earthquake with a magnitude of around 6 can be expected on average every 50 to 150 years. The last earthquake of this magnitude occurred in 1946 near Sierre in Valais.
The strongest earthquake in Switzerland to date, the Basel earthquake in 1356 , had a magnitude of around 6.6 and destroyed large parts of the city of Basel in 1356. If there were to be a similar earthquake in Basel today, several thousand fatalities, tens of thousands of seriously and slightly injured people and property damage of up to 140 billion Swiss francs would be expected.
The best protection against the effects of an earthquake is an earthquake-proof construction and securing objects that could fall. In Switzerland, it is unclear to what extent 90 percent of buildings can withstand a strong earthquake. Only a few cantons legally stipulate compliance with building standards for earthquake-proof construction.
Alerting in the event of an incident
Earthquakes can neither be predicted nor prevented. However, the SED continuously records the vibrations of the ground. Within about 90 seconds, information on the time, place, strength and possible effects of an earthquake appears on the website www.seismo.ethz.ch. From a magnitude of 2.5, earthquake reports are also published on the SED @seismoCH_D Twitter channel, on the MeteoSchweiz app and on naturgefahren.ch.
The SED automatically reports any noticeable earthquakes to the authorities and the media. At the same time, this information is sent to the SED's 24-hour on-call service via pager, e-mail and SMS. This is available to authorities and the media for further information on current earthquakes and compiles background information that is published on the website. In the event of major earthquakes, the SED also informs the Swiss Humanitarian Aid Corps (SH).
Research and Teaching
In addition to earthquake monitoring and earthquake risk assessment, the SED researchers take part in many national and international research projects, most of which are financed by third-party funds. This guarantees a lively professional exchange across national borders. Areas in which the researchers at the SED are involved are, for example, glacial and engineering seismology, statistical seismology , induced seismicity, the monitoring of rockfalls and seismotectonics. The aim of research at the SED is primarily to better understand earthquakes and their effects and thus to make a contribution to dealing with this natural hazard, which is a global threat. At the same time, innovative ways are being sought to learn more about fundamental processes on earth using seismological methods. The training of young researchers also plays an important role for the SED. This takes place in the form of lectures and seminars that are integrated into the teaching activities of the ETH, as well as the supervision of master's and doctoral theses.
Nuclear test stop monitoring
In 1996, the UN states agreed to draw up a treaty banning atomic weapons. An international monitoring system was set up to check compliance with this contract.
The SED is making a contribution by supplying the organization of the Treaty on the Comprehensive Nuclear-Test-Ban Treaty in Vienna with data recorded by the specially built seismic station in the Dischmatal near Davos. At this station, for example, ground vibrations were registered just twelve minutes after the nuclear weapons test in North Korea in February 2013.
Web links
Individual evidence
- ↑ Earthquake prevention measures. Retrieved May 6, 2018 .
- ^ History of the Swiss Seismological Service. In: www.seismo.ethz.ch. Retrieved November 3, 2016 .
- ↑ SED | Monitoring. Retrieved March 24, 2020 .
- ↑ Seismic hazard and risk. In: www.seismo.ethz.ch. Retrieved November 3, 2016 .
- ^ Scenario earthquake in Basel. In: www.seismo.ethz.ch. Retrieved November 3, 2016 .
- ↑ Alerting. In: www.seismo.ethz.ch. Retrieved February 4, 2014 .
- ↑ Research and teaching. In: www.seismo.ethz.ch. Retrieved November 3, 2016 .
- ↑ Verification of nuclear tests. In: www.seismo.ethz.ch. Retrieved November 3, 2016 .