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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?
2017-04-25  12:35 2.8 Grenchen SO Felt

Latest Earthquakes

Local Time
Magnitude
Location
2017-04-26 23:29 1.6 Lago d'Iseo I
2017-04-25 12:40 1.2 Grenchen SO
2017-04-25 12:35 2.8 Grenchen SO
2017-04-24 01:59 1.3 Vaduz FL
2017-04-23 20:25 1.7 Porrentruy JU
2017-04-23 11:41 1.5 Frick AG

Swiss Earthquakes Counter

since 01.01.2017 
000

Recent earthquakes magnitude 4.5 or greater

Time (UTC)
Mag.
Region
2017-04-21 14:12:22 4.9 Turkey
2017-04-21 13:09:22 5.0 Turkey
2017-04-15 23:55:23 4.5 Mar Ionio Meridionale (MARE)
2017-04-13 16:22:16 5.0 WESTERN TURKEY
2017-04-08 22:23:12 4.6 Poland
2017-04-08 13:53:02 5.0 ALBANIA
2017-04-05 15:43:29 4.8 Greece
2017-03-29 18:10:45 4.5 Turkey
2017-03-26 01:48:41 4.9 ICELAND REGION
2017-03-26 01:07:12 4.9 ICELAND REGION
2017-03-26 00:24:50 4.6 ICELAND REGION
2017-03-24 08:54:25 4.5 Turkey
2017-03-24 04:24:30 4.6 Southern Greece

Recent earthquakes magnitude 6 or greater

UTC Time
Magnitude
Location
2017-04-24 21:38:26 6.9 Off coast of central Chile
2017-04-18 17:11:47 6.0 Fiji Islands region
2017-04-15 08:19:41 6.2 Chile-Argentina border region
2017-04-05 06:09:12 6.1 Northern and central Iran
2017-04-03 17:40:18 6.5 Botswana
2017-03-29 04:09:23 6.6 Near east coast of Kamchatka Peninsula, Russia
2017-03-27 10:50:19 6.1 Near Islands, Aleutian Islands, United States
2017-03-19 15:43:25 6.0 Bougainville - Solomon Islands region
NEWS

04/21/2017

Researching Induced Seismicity

Researching Induced Seismicity

Exploiting resources buried deep underground is no easy matter. Indeed, it can only be successful if a number of different factors fall into place. One frequently discussed problem concerns earthquakes that can be triggered by human activity in the subsurface. In March, more than 150 international researchers met up for the second Schatzalp workshop organised in Davos by the Swiss Seismological Service to exchange their views and findings on induced seismicity. Click here for all the posters on display and the presentations made at this workshop.

recently published overview study investigating the current challenges associated with monitoring and handling induced seismicity showed that real-time monitoring of seismic activities in the subsurface is still not standard practice in many places. This makes it difficult to intervene promptly and take preventive measures. Furthermore, there are no standardised requirements or international norms regarding such monitoring, which especially creates difficulties for projects carried out in border areas.

03/29/2017

Opening of a geothermal borehole in Basel

On 28 March 2017, in consultation with Basel Industrielle Werke (IWB) the Department of Health of the Canton of Basel decided to re-open the borehole created in Basel as part of the "Deep Heat Mining" geothermal power project in 2006. The decision was prompted by an increase in microearthquake activity in the immediate vicinity of the borehole over the past few months. An extensive scientific study by the Swiss Seismological Service (SED) at the ETH Zurich revealed that the increased earthquake activity will most probably subside again in the long term if the borehole is opened.

The geothermal project in Basel launched in 2006 sought to create an artificial fracture system in rock 4,000-5,000 m underground to use as a geothermal reservoir for power generation. To this end, cold water was injected into the substrate under high pressure. In the course of this process, a large number of microearthquakes occurred, some of them noticeable, and one earthquake with a magnitude of 3.4 magnitude (ML), which caused minor damage to buildings. As a result, work on the project was interrupted and then stopped altogether in 2009 after a comprehensive risk analysis. The borehole was opened in December 2006 after increased seismicity, and closed again in April 2011.

Earthquake activity in the vicinity of the borehole has been monitored by a seismic network since the start of the project. The indications from the amassed data are that seismic activity in the stimulated area has more or less continually decreased since the project ended in 2006. Roughly a year after the closure of the borehole in April 2011, seismic activity in the immediate vicinity of the borehole markedly increased again. This increase has been particularly noticeable since the second half of 2016 and typically consisted of swarms of microearthquakes, with phases of increased activity over a number of weeks being followed by quieter periods. So far, none of these earthquakes were felt by the public.

Apart from the seismic activity, in recent months the spatial distribution of the quakes has also shifted. The latest earthquakes occurred at the southern and northern edges of the previously affected area, suggesting that the artificially induced fractures are spreading. In addition, measurements show that the hydraulic pressure in the reservoir (pore pressure) has steadily increased since the borehole was closed. A detailed analysis of the seismic data and modelling of the relationship between earthquakes and increasing pore pressure have shown that even modest pressure increases in the reservoir can significantly increase seismicity.

Analyses performed by the Swiss Seismological Service (SED) show that a noticeable minor earthquake with a magnitude of 2 may well occur within the next 12 months unless steps are taken to lower the pressure. The probability of this happening is between 55% and 85%. The current probability of an earthquake as strong as the one that occurred in 2006, which had a magnitude of 3.4, is around 5%. Based on its modelling and the decline in seismicity observed between 2007 and 2011, the SED expects that opening the borehole for the next one or two years should lower the average seismicity rate by between 50% and 90% percent.

Over the past decade, the SED has advised and supported project operators and in particular cantonal authorities (e.g. Basel-Stadt, Jura, Vaud, Thurgau and the city of St. Gallen) on deep geothermics. This work focussed on seismological aspects of the environmental impact assessment (EIA), seismic monitoring and the review of operational and seismic safety concepts.

Learn more

Background report on induced earthquakes within area covered by the geothermal project in Basel (in German)

Press release by the Canton of Basel Stadt on the opening of the borehole (in German)

SED information on the geothermal project in Basel

Earthquakes and geothermal energy – a brief explanation of key correlations

03/20/2017

Two Felt Earthquakes Near Vallorcine (F)

Two earthquakes occurred near Vallorcine (F), close to the Swiss border on 20 March 2017. Both events were widely felt in the epicentral area as well as in the lower Valais between Martigny and Monthey. The first earthquake had a magnitude of 3.3 and happened at 1:31 h. The second earthquake, with a magnitude of 3.0, occurred at 22:09 h. The distance between the epicenters of two events is a few hundred meters. In general, earthquakes of this magnitude do not cause any damage. The region of Vallorcine has seen about a dozen of felt earthquakes since an earthquake with a magnitude of 4.9 on September 8, 2005.

03/06/2017

Summary of the magnitude 4.6 Urnerboden Earthquake

Summary of the magnitude 4.6 Urnerboden Earthquake

The epicenter of the Magnitude 4.6 (local or Richter magnitude ML) earthquake of 2017/03/06 21:12 local time is located about 3 km NE of the village of Urnerboden in the border region of cantons Uri, Schwyz, and Glarus. The preliminary focal depth is determined to be about 5 km. The Ml 4.6 earthquake was preceded by several foreshocks with ML ranging between 0.2 to 2.2. In the first 12 hours after the ML 4.6 event, the SED recorded about 25 aftershocks with magnitudes between ML 0.5 and 2.9. Further aftershocks, some of them perceptible, are expected over the coming days. Earthquakes with a similar or even larger magnitude than the current main shock are unlikely, but cannot be excluded.

The shaking from this event was felt by the majority of people across Central Switzerland. The Swiss Seismological Service also received more than 5000 earthquake reports from a region of about 200 km diameter, including Ticino and the cantons of Bern, Aargau, Basel, Zurich and Grisons up to Chur. The high public interest was evident also in the up to 500’000 requests per minute on the SED websites. This high demand led to the SED's web pages partially not being accessible in the first 40 minutes after the event, and after that for some time with delays.

The epicenter is located in the Helvetic nappes. The preliminary focal depth of 5 km indicates a source at the border of the sedimentary cover and the crystalline basement. The moment tensor solution for this earthquake indicates it had a moment magnitude of MW 4.1 with a strike-slip mechanism, with either a NNW-SSE or WSW-ENE striking fault plane, consistent with other events in this region. These mechanisms indicate northwest-southeast oriented compression of the crust in this region of the Helvetic domain. Last night’s earthquake occurred close to the magnitude 4.0 (ML) Urnerboden earthquake of 5 May 2003. The depth and the focal mechanism of that event are very similar to yesterday’s earthquake and it seems likely that both events are associated with the same fault system.

Generally speaking, tectonic stresses in the Alps are the result of the collision between the European and the African lithospheric plates. However, due to the complex tectonic structure and history of the Alpine collision zone, significant along-strike variations in the tectonic regimes are observed.

The highest acceleration measured by seismic instruments were reported from Linthal (GL) and reached 85 cm/s2. On average, earthquakes of this size happen approximately once every 5 years in Switzerland. The last earthquake with a similarly large magnitude was the Vallorcine (F) (4.9 ML) event close to the Swiss border near Martigny (VS) on 8 September, 2005. It was strongly felt in the Valais.

On Wednesday 7 March, the SED installed two additional stations at Urnerboden and Bisisthal. These stations will allow characterizing the aftershock sequence and thus the properties of the activated fault in more detail.

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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 500 and 800 earthquakes a year, around 10 of which are powerful enough (with a magnitude of approximately 2.5 or higher) to be felt by the country's inhabitants. 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 times a year on average 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 150 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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