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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?
2019-10-17 11:46 1.9 Brugg AG Probably not felt
2019-09-28 14:53 2.7 Goeschenen UR Slightly felt
2019-09-21 10:18 2.1 Stein am Rhein SH Slightly felt

Latest Earthquakes

Local Time
Magnitude
Location
2019-10-19 04:28 1.2 Chamonix F
2019-10-19 04:00 1.9 Colmar F
2019-10-19 03:57 0.7 Chamonix F
2019-10-19 00:04 0.2 Courmayeur I

Swiss Earthquakes Counter

since 01.01.2019 
000

Recent earthquakes magnitude 4.5 or greater

Time (UTC)
Mag.
Region
2019-10-12 17:21:23 4.9 WESTERN IRAN
2019-10-12 06:49:35 4.5 IONIAN SEA
2019-10-11 22:43:18 4.5 IONIAN SEA
2019-10-05 14:51:38 4.5 Eastern Mediterranean Sea
2019-10-03 04:44:56 5.1 DODECANESE IS.-TURKEY BORDER REG
2019-09-26 20:02:41 4.5 Turkey
2019-09-26 10:59:25 5.7 WESTERN TURKEY
2019-09-25 15:21:50 4.5 EASTERN MEDITERRANEAN SEA
2019-09-24 13:38:14 4.6 North Sea
2019-09-24 09:02:00 4.7 Western Iran
2019-09-24 08:00:24 4.9 Turkey
2019-09-24 07:48:58 5.6 CRETE, GREECE
2019-09-22 20:08:41 4.5 Albania

Recent earthquakes magnitude 6 or greater

UTC Time
Magnitude
Location
2019-10-16 11:37:06 6.4 Mindanao, Philippine Islands
2019-09-29 15:57:53 6.7 Off coast of central Chile
2019-09-29 02:02:52 6.2 Mindanao, Philippine Islands
2019-09-27 12:05:02 6.0 Kermadec Islands, New Zealand
2019-09-26 16:36:18 6.1 Central Chile
2019-09-25 23:46:44 6.5 Seram, Indonesia
2019-09-24 21:19:47 6.1 Southwest Indian Ridge
2019-09-24 03:23:35 6.0 Mona Passage
NEWS

2019-10-11

Research project funded to better understand earthquakes

Research project funded to better understand earthquakes

Despite intensive research, scientists cannot predict exactly when and where the next major earthquake will occur. Domenico Giardini, ETH Professor of Seismology and Geodynamics, Florian Amann of RWTH Aachen University, Stefan Wiemer, Director of the Swiss Seismological Service at ETH Zurich, and Massimo Cocco of the Instituto Nazionale di Geofisica e Vulcanologia, Italy, want to better understand the physics of earthquake processes with their ERC Synergy project "FEAR".

The rock laboratory "Bedretto Lab" in the Swiss Alps, built by ETH Zurich and the Werner Siemens Foundation, offers FEAR a unique research environment. The researchers will generate small earthquakes under controlled conditions at a depth of more than one kilometre and on a scale of ten to one hundred metres. They will measure a variety of earthquake parameters using a dense sensor network and then analyse them. The consortium hopes to gain a better understanding of the dynamics of earthquakes. The new findings will also be used to advance experiments on the safe use of geo-energy and to improve the predictability of earthquakes.

2019-10-09

Was that the main quake?

Was that the main quake?

Whereas most major earthquakes are not preceded by foreshocks, they are always followed by thousands of aftershocks, whose frequency and magnitude fade over time. However, in some cases a major earthquake is followed by an even more powerful one. This was what happened in the sequences of earthquakes that hit Central Italy in 2016 or Ridgecrest, California (USA) in July 2019.

Up to now, there was no way of predicting whether a powerful earthquake was likely to be followed by one of even greater magnitude. But the results of a study recently published in Nature by Laura Gulia and Stefan Wiemer from the Swiss Seismological Service (SED) at ETH Zurich awaken hopes that we will soon be able to do just that, in real time. Such a scientific discovery would have far-reaching consequences for civil protection, enabling more reliable decisions about evacuating people, allowing rescue workers to target their efforts accordingly, and permitting the implementation of measures to secure critical infrastructure, such as power stations.

Based on recent seismic data, the authors of the study have devised a method that can be used to determine whether a sequence of earthquakes is rather ending or will be followed by an even more powerful earthquake. The relevant parameter they examined was the so-called b-value, which characterises the relationship between the magnitude and number of quakes. Laboratory measurements show that this value indirectly indicates the state of stress in the Earth's crust. In seismically active regions the b-value is usually close to 1, meaning that there are about 10 times as many magnitude 3 earthquakes than quakes with a magnitude of 4 or higher.

The researchers have now demonstrated that the b-value changes systematically in the course of an earthquake sequence. To prove this, they examined data from 58 sequences and came up with a traffic-light system indicating what would happen next. When the b-value drops by 10 percent or more, the traffic light turns red, suggesting acute danger of an even more powerful quake. In most cases, though, the b-value rises by 10 percent or more and the traffic light turns green, giving the all-clear by predicting a typical sequence that will gradually fade away. This happened in 80 percent of the sequences captured in datasets examined by the researchers. The traffic light shows amber when the b-value rises or falls by less than 10 percent, meaning it is unclear what will happen next.

The traffic-light system devised by the researchers turned out to be accurate in 95 percent of the cases they examined. The observed change in the b-value betrayed how a sequence would develop, indicating whether or not an even more powerful earthquake would follow. That said, their findings will have to be verified by examining other datasets before such a system can actually be used for civil protection. The system's successful deployment would also require a dense seismic network and corresponding data processing capacity. By no means all regions that could benefit from such a traffic-light system currently have these things.

Nature article Real-time discrimination of earthquake foreshocks and aftershocks

2019-09-25

Swiss contribution to advance the ShakeAlert earthquake early warning system in the U. S.

Swiss contribution to advance the ShakeAlert earthquake early warning system in the U. S.

Imagine receiving a warning about imminent earthquake shaking before you feel it. Sounds like science fiction? Not quite: In Japan and Mexico such systems are established and in operation for several years. Along the West Coast of the United States such a system, called ShakeAlert, is currently in the first phase of a public roll-out. The US Geological Survey (USGS) awarded funding to several institutions, including the Swiss Seismological Service (SED) at ETH Zurich, to get ShakeAlert ready for public alerting.

ShakeAlert is an earthquake early warning system for the West Coast of the United States. It has been developed over a period of 13 years and is currently being tested by selected commercial and institutional users. In a next step, with the additional funding awarded by the USGS, ShakeAlert will be made publicly available to a much larger group that will, for example, be alerted via cell phones. This requires improvement of ShakeAlert in several ways: for example, the upgrade of sensor networks, the advancement of algorithms, and public education.

ShakeAlert uses two algorithms: EPIC and FinDer. EPIC estimates the (point-source) hypocenter and the magnitude of the earthquake. With stronger earthquakes (magnitude 6 and larger), the fault rupture typically spans several tens to hundreds of kilometres. This is why ShakeAlert uses the second algorithm, FinDer. This algorithm is able to estimate in real-time the dimensions of the rupture zone along a fault, which is crucial to estimate the ground shaking as accurately as possible. Maren Böse, a senior research scientist at the Swiss Seismological Service, has developed FinDer. The USGS awarded her to conduct research to improve the performance of FinDer in collaboration with the USGS and California Institute of Technology (Caltech). Her research will focus in particular on the mitigation of large earthquakes along the San Andreas Fault and the Cascadia subduction-zone, which have huge damage potential.

Earthquake early warning systems like ShakeAlert do not predict earthquakes, but rather indicate that an earthquake has begun and that shaking is imminent. This gives people, at best, a precious few to several tens of seconds to take actions before the shaking begins. Early warning systems can also trigger automated actions, such as slowing down trains or stopping elevators. However, there is often not enough time to issue a warning in time. In addition, people who are directly at the epicentre do not benefit from a warning, as the damaging waves arrive before.

Learn more about earthquake early warning and FinDer.

Learn more about ShakeAlert here.

Figure: FinDer line-source model for the 6 July 2019 M7.1 Ridgecrest earthquake, California (USA).

2019-09-05

[Available in DE/FR] Erneut verspürtes Beben bei Konstanz

[Available in DE/FR] Erneut verspürtes Beben bei Konstanz

Am Donnerstag, 29. August 2019 hat sich um 16:22 Uhr (Lokalzeit) erneut ein Beben auf der Halbinsel Bodanrück ereignet. Das Beben wies eine Magnitude von 3.5 auf und ereignete sich in einer Tiefe von etwa 4 Kilometern. Beim Schweizerischen Erdbebendienst an der ETH Zürich sind in den ersten Minuten nach dem Beben etwa 30 Verspürtmeldungen eingegangen.

Das Beben ist Teil einer derzeit aktiven Erdbebensequenz auf der Halbinsel, die etwa 10 km nordwestlich von Konstanz (D) liegt. Das bisher stärkste Beben mit einer Magnitude von 3.7 ereignete sich am 30. Juli 2019. Diesem Hauptbeben ging ein spürbares Beben der Stärke 2.9 voraus. In der Folge wurden einige Nachbeben registriert.

Weitere Informationen zur Erdbebensequenz auf der Halbinsel Bodanrück finden Sie in diesem Beitrag.

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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