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Swiss Seismological Service (SED)

The Swiss Seismological Service (SED) at ETH Zurich is the federal agency for earthquakes. Its activities are integrated in the federal action plan for earthquake precaution.

Felt Earthquakes in Switzerland

Local Time
Mag.
Location
Felt?
2020-09-03 22:36 2.5 Courmayeur I Probably not felt
2020-09-03 11:42 2.1 Brugg AG Probably not felt

Latest Earthquakes

Local Time
Magnitude
Location
2020-09-29 07:59 0.3 Bourg-Saint-Pierre VS
2020-09-28 21:35 0.7 Sierre VS
2020-09-28 17:13 0.5 Courmayeur I
2020-09-28 08:41 0.4 Courmayeur I
2020-09-28 05:43 0.6 Courmayeur I

Swiss Earthquakes Counter

since 01.01.2020 
000

Recent earthquakes magnitude 4.5 or greater

Time (UTC)
Mag.
Region
2020-09-29 03:10:48 4.7 Greenland Sea
2020-09-28 04:12:41 4.8 Aegean Sea
2020-09-27 16:05:08 4.5 Aegean Sea
2020-09-27 12:58:01 4.5 AEGEAN SEA
2020-09-27 12:22:20 4.7 Aegean Sea
2020-09-27 10:02:38 4.6 Greenland Sea
2020-09-27 00:06:09 4.7 Iceland
2020-09-26 22:50:24 5.2 AEGEAN SEA
2020-09-26 18:39:18 4.5 Aegean Sea
2020-09-24 19:21:39 4.5 ALBANIA
2020-09-24 18:52:13 4.5 CRETE, GREECE
2020-09-24 05:10:20 4.6 Greece
2020-09-24 04:44:58 4.5 Greenland Sea

Recent earthquakes magnitude 6 or greater

UTC Time
Magnitude
Location
2020-09-26 17:10:22 6.1 South of Africa
2020-09-18 21:43:58 6.9 Central Mid-Atlantic Ridge
2020-09-15 04:12:16 6.0 Fiji Islands
2020-09-15 03:41:28 6.4 Kamchatka Peninsula, Russia
2020-09-12 02:44:10 6.1 Near east coast of eastern Honshu, Japan
2020-09-12 02:37:00 6.0 Fiji Islands region
2020-09-11 07:35:57 6.2 Northern Chile
2020-09-11 07:35:55 6.5 Northern Chile
NEWS

2020-09-24

Updated earthquake-resistant construction standards

Updated earthquake-resistant construction standards

Structures designed to be earthquake-resistant provide the best protection from the effects of an earthquake. The specifications for such structures in Switzerland are laid down in SIA 261: Actions on Structures, a standard produced by the Swiss Society of Engineers and Architects (SIA). A revised version recently came into force, taking into account new data from the seismic hazard model updated in 2015 by the Swiss Seismological Service (SED) at ETH Zurich. The main adjustments relate to the map of earthquake zones and the response spectra for various subsoil categories. In order to better protect buildings with vital infrastructure functions (building class III, e.g. acute care hospitals), the safety factors required to prove the structural safety and serviceability of these buildings have also been increased slightly.

Based on a more fine-grained seismic hazard map, the earthquake zone map now divides Switzerland into five areas, each with differing requirements when it comes to earthquake-resistant construction. This is one more zone than before. The zone boundaries have also been adjusted based on the new findings from the updated seismic hazard model.

Engineers use response spectra to work out the design requirements for structures on various substrates (which are divided into subsoil categories for the purpose of the standards). Based on these response spectra, they identify the measures that need to be implemented to ensure that a structure built on the subsoil at a given location complies with the standards. The adjustments made to the response spectra in the revised standard are based on an in-depth analysis of earthquake recordings at many seismic stations together with geophysical measurements determining the local properties of the subsoil at the station locations. The standard takes account of the fact that loosely deposited sediments amplify the seismic waves. As a result, structures at such locations must be designed to withstand stronger ground movements.

In Switzerland, cantons are responsible for checking compliance with construction standards. In some cantons, building legislation explicitly requires compliance with the applicable SIA standards or lays down earthquake-specific requirements as part of the planning permission process. In others, implementation is not explicitly regulated by law and is not monitored either. According to the Swiss Federal Office for the Environment, the additional costs involved in making a structure earthquake-resistant represent no more than 1% of the total, provided that this is factored into the design at an early stage.

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Earthquake-Resistant Construction

Seismic Hazard in Switzerland

SIA 261 (in German, French and Italian)

2020-08-20

A new-look Natural Hazards Portal to keep Switzerland informed

A new-look Natural Hazards Portal to keep Switzerland informed

Earthquakes are not the only natural hazard that Switzerland needs to really focus on. The country's topography and geography mean that it is prone to a variety of major natural hazards. The public must be warned in good time of storms sweeping across Switzerland, forest fires, or avalanches thundering down mountain slopes. They must also receive alerts about earthquakes as quickly as possible. Notifying the public of these events is the task of the federal agencies responsible for monitoring natural hazards. They provide up-to-date information on such hazards via the Natural Hazards Portal at www.natural-hazards.ch. These agencies have made various adjustments and improvements to this site to create a new-look portal, which is now being released.

Time and again, Switzerland is faced with natural events that have the potential to endanger human life and infrastructure. In light of this, the federal agencies responsible for monitoring natural hazards have joined forces to ensure that the public is adequately informed, warned and protected in such critical situations. They publish warnings about storms, heavy precipitation and snowfall, slippery roads, ground frost, heat waves, thunderstorms, forest fires, floods and avalanches, and issue alerts regarding current earthquakes.

The agencies jointly operate the Natural Hazards Portal with the aim of reaching as many people as possible when a natural event occurs and providing them with standardised information. Furthermore, they publish all warnings and alerts about natural hazards on this website and also issue these warnings and alerts through the MeteoSwiss app. As a result, reliable and consolidated information on current natural hazards situations and events is available to the public.

Following a revamp, a new-look Natural Hazards Portal is now being released. The updated portal features adjustments to how hazards are shown and illustrations depicting recommended behaviours. For example, rivers and lakes of national interest are now colour-coded based on their warning status, making this easier to see, while forest-fire risk is now shown along cantonal borders, with pictograms on key recommended behaviours making this information more user-friendly.

The federal agencies responsible for monitoring natural hazards firmly believe that these adjustments will help the Swiss public to locate the relevant information more easily and understand it more readily, both before and during natural hazards events.

The Federal Office for the Environment (FOEN), the Federal Office of Meteorology and Climatology (MeteoSwiss), the WSL Institute for Snow and Avalanche Research (SLF), the Swiss Seismological Service (SED) at ETH Zurich and the Federal Office for Civil Protection (FOCP) are officially mandated by the federal government to provide information and issue warnings to the public, the media and the authorities about impending natural hazards. In critical situations, the natural hazard agencies work particularly closely together, coordinating their forecasts and warnings and compiling joint press releases and bulletins about natural hazards.

You can find further information at www.natural-hazards.ch.

This text was adapted, with permission, from a MeteoSwiss blog entry (German).

2020-08-13

[Available in DE / FR] Erdbeben bei Zermatt

[Available in DE / FR] Erdbeben bei Zermatt

Am Mittwoch, dem 12. August 2020, hat sich um 23:15 Uhr Ortszeit ca. 3 km westlich von Zermatt (VS), in einer geringen Tiefe von ungefähr 3 km, ein Erdbeben der Magnitude 3.0 ereignet.

Die Erschütterung war fast ausschliesslich im nahen Epizentralgebiet, also vor allem in Zermatt selbst, gut zu spüren. Die am Schweizerischen Erdbebendienst der ETH Zürich eingegangenen Meldungen berichten von einer kurzen, nicht besonders angsteinflössenden Vibration. Bei einem Erdbeben dieser Stärke sind in der Regel keine Schäden zu erwarten.

Das Wallis ist das Gebiet der Schweiz mit der stärksten Erdbebengefährdung, im Wallis selbst gehören Saastal und Mattertal aber nicht zu den exponiertesten Zonen. Das letzte verspürte Beben im Gebiet ereignete sich am 21.7.2018 10 km östlich von Zermatt. Es hatte eine Magnitude von 2.6.

2020-07-24

COVID-19 pandemic reduces seismic noise worldwide

Research recently published in the journal Science has shown that lockdown measures to combat the spread of COVID-19 lead to a 50% reduction in seismic noise observed around the world in early to mid-2020. In Switzerland, researchers from the Swiss Seismological Service (SED) at ETH Zurich were also able to identify this phenomenon, as the SED announced in an earlier news item in April 2020. The SED, therefore, participated in the international study, in which a total of 76 authors from 66 institutions in 27 countries collaborated.

By analysing month-to-years long datasets from over 300 seismic stations around the world, the study, led by Dr Thomas Lecocq from the Royal Observatory of Belgium, was able to show how the seismic noise decreased in many countries and regions since the start of the lockdown measures. The researchers could visualise the resulting "wave of quiet” moving through China, then to Italy, and around the rest of the world. The seismic lockdown sees the total effect of physical and social distancing measures, reduced economic and industrial activity and drops in tourism and travel. The 2020 seismic noise quiet period is the longest and most prominent global anthropogenic seismic noise reduction on record.

Traditionally, seismology focuses on measuring and analysing seismic waves arising from earthquakes. High-frequency vibrations (“buzz”) of human activity, however, contaminate the seismic records from natural sources. Walking around, driving cars, and getting the train, but also heavy industry and construction work generate unique seismic signals in the subsurface that influence the recordings of natural phenomena. The strongest seismic noise reductions from the COVID-19 lockdown were found in urban areas, but the study also observed signs of the lockdown on sensors installed hundreds of meters below the surface and in more remote areas, such as in sub-Saharan Africa. Furthermore, the researchers found a strong correlation between seismic noise reduction and human mobility datasets.

In Switzerland, in particular the stations belonging to the Swiss Strong Motion Network (SSMNet) did show similar effects. Many of these measuring stations are located in urban areas and a significant reduction in seismic noise was recorded in Lugano, Martigny, Zurich, Basel and Geneva, among others. Since the lockdown was declared in mid-March, levels of seismic noise in these towns and cities have been nearly as low on working days as they were during weekends before the lockdown began. Meanwhile, the seismic noise is back to almost normal levels in Switzerland and in most countries analysed in the study.

Will the 2020 seismic noise quiet period allow new types of signals to be detected? The study has shown the first evidence that previously concealed earthquake signals, especially during the daytime, appeared much clearer on seismic sensors in urban areas during the lockdown. In Switzerland, the overall effect is a decrease in the detection threshold for earthquakes by about 0.1 - 0.2 magnitude units across the country, for many urban areas this decrease is even greater at 0.3 magnitude units or more.

SED seismologist Dr Frédérick Massin, one of the co-authors of the study, says that the researchers hope that their work will spawn further research on the seismic lockdown. Finding previously hidden signals from earthquakes and volcanoes will be one key goal. Due to the growing urbanisation and increasing populations, it becomes more important than ever to characterise the anthropogenic noise humans cause so that seismologists can better listen to the Earth, especially in cities, and monitor the ground movements beneath our feet.

More information: https://science.sciencemag.org/lookup/doi/10.1126/science.abd2438

TOPICS

Earthquake

Help, the Earth Is Shaking!

Help, the Earth Is Shaking!

Earthquakes are inevitable, but the damage they may be expected to cause can be mitigated in relatively simple ways. Find out the recommended behaviour before, during and after a powerful earthquake.

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Knowledge

Earthquake Country Switzerland

Earthquake Country Switzerland

Switzerland experiences between 1'000 and 1'500 earthquakes a year. Swiss citizens actually feel somewhere between 10 and 20 quakes a year, usually those with a magnitude of 2.5 or above. Based on the long-term average, 23 quakes with a magnitude of 2.5 or above occur every year. Find out more about the natural hazards with the greatest damage-causing potential in Switzerland.

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Alerting

Always Informed

Always Informed

If you want to be kept informed at all times, here you will find an overview of the various information services provided by the Swiss Seismological Service (SED).

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Knowledge

Earthquake Hazard

Earthquake Hazard

In Switzerland, earthquakes are the natural hazard with the greatest potential for causing damage. They cannot currently be prevented or reliably predicted. But, thanks to extensive research, much is now known about how often and how intensely the earth could shake at a given location in the future. Consult a variety of different maps using our interactive web tool to find out how likely certain earthquakes are in Switzerland.

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Research & Teaching

Fields of Research

Fields of Research

We are often asked what staff at the SED do when no earthquakes are occurring. The answer is they conduct research in a variety of fields, constituting SED's main scientific activities described in our research field section.

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About Us

Swiss Seismological Service (SED)

Swiss Seismological Service (SED)

The Swiss Seismological Service (SED) at ETH Zurich is the federal agency responsible for monitoring earthquakes in Switzerland and its neighboring countries and for assessing Switzerland’s seismic hazard. When an earthquake happens, the SED informs the public, authorities, and the media about the earthquake’s location, magnitude, and possible consequences. The activities of the SED are integrated in the federal action plan for earthquake precaution.

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Earthquakes

Earthquake Monitoring

Earthquake Monitoring

Around 10 to 20 times a year you will hear or read about an earthquake occurring in Switzerland. However, the vast majority of quakes recorded by the SED go unnoticed by the general public because they fall below the threshold of human perception and can only be detected by sensitive measuring devices. The Swiss Seismological Service (SED) operates a network of more than 200 seismic stations across Switzerland.

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Research and Teaching

Products and Software

Products and Software

Go to our Products page for access to seismic data and various apps.

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