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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?
2019-02-16 19:50 2.7 Bourg-Saint-Pierre VS Probably not felt
2019-02-05 22:52 2.9 Bellegarde-sur-Valserine F Probably not felt
2019-02-05 22:32 3.2 Bellegarde-sur-Valserine F Slightly felt
2019-02-05 10:52 2.8 Courmayeur I Probably not felt
2019-02-05 09:30 3.1 Courmayeur I Slightly felt
2019-01-29 18:30 2.1 Sargans SG Felt

Latest Earthquakes

Local Time
Magnitude
Location
2019-02-19 07:37 2.3 Valdaron F
2019-02-18 11:48 1.5 Courmayeur I
2019-02-18 09:28 2.0 Tavannes BE
2019-02-18 06:32 1.1 Graechen VS

Swiss Earthquakes Counter

since 01.01.2019 
000

Recent earthquakes magnitude 4.5 or greater

Time (UTC)
Mag.
Region
2019-02-17 21:40:03 4.5 Ionian Sea
2019-02-17 19:07:42 4.8 Southern Greece
2019-02-12 17:14:31 4.8 Turkey
2019-02-09 21:26:22 4.8 Western Iran
2019-02-05 19:31:37 5.0 AZERBAIJAN
2019-02-05 19:20:00 4.5 AZERBAIJAN
2019-02-05 15:11:51 4.5 Turkey
2019-02-05 02:26:08 5.2 GREECE
2019-02-02 14:09:25 4.5 Crete, Greece
2019-02-02 12:20:38 4.5 CENTRAL TURKEY
2019-02-02 10:13:38 4.6 Jan Mayen Island region
2019-02-02 09:18:48 4.9 JAN MAYEN ISLAND REGION
2019-02-01 10:29:47 4.9 Dodecanese Islands, Greece

Recent earthquakes magnitude 6 or greater

UTC Time
Magnitude
Location
2019-02-17 14:35:55 6.3 New Ireland, Papua New Guinea, region
2019-02-17 14:35:46 6.5 Palau region
2019-02-14 19:57:05 6.2 Northern Mid-Atlantic Ridge
2019-02-02 09:27:34 6.1 Southern Sumatera, Indonesia
2019-02-01 16:14:13 6.6 Near coast of Chiapas, Mexico
2019-01-26 19:56:44 6.2 Fiji Islands region
2019-01-26 03:51:38 6.2 Bougainville - Solomon Islands region
2019-01-22 19:01:43 6.7 Prince Edward Islands, South Africa, region
NEWS

2019-02-04

Can deep boreholes trigger earthquakes?

Can deep boreholes trigger earthquakes?

More than 100 deep boreholes have already been drilled to depths of 400 m or more in Switzerland. Among other things, they have served to explore the subsoil, whether for tunnelling, exploiting geothermal energy, as potential sites for final repositories, prospecting for raw materials or tapping into sources of groundwater and thermal water. Hundreds of thousands of such boreholes have been sunk all over the world. So far, to our knowledge, no damaging earthquakes have been triggered solely by drilling deep boreholes. Consequently, the simple answer to the question asked above is that instances of damage caused solely by sinking deep boreholes, without any further interventions in the subsoil, are extremely unlikely. However, micro-earthquakes with magnitudes of less than 1 have been documented in association with the drilling of deep boreholes. Thanks to a dense seismic network, such microquakes can be reliably recorded. It can then be better determined whether such seisms are related to the sinking of deep boreholes or triggered by natural causes.

Despite the very large number of deep boreholes drilled worldwide, data on earthquakes occurring in connection with them are rather sparse. One reason for this is that the probability of such quakes is very low. Another is that many deep boreholes have been drilled in uninhabited areas, so potentially noticeable quakes may not have been felt and reported by the public. In many places, such boreholes have not been - and are still not being - seismically monitored. Consequently, it is impossible to reliably record smaller induced earthquakes. In Switzerland, for example, a number of microquakes were recorded when the borehole for the Basel geothermal energy project was cemented. The strongest of these had a magnitude of 0.7, meaning that it released 500 times less energy than a magnitude 2.5 quake. Earthquakes above this magnitude can usually be felt.

The physical processes behind earthquakes triggered in certain circumstances by drilling boreholes are well understood. Deep boreholes sometimes alter local stresses and pore pressures in rock, and in some cases this can reactivate a nearby tectonically pre-stressed fracture, causing an earthquake. However, such stress changes usually only occur in the following two situations: firstly, when drilling into a stratum with high fluid pressures. In this case, under certain conditions, the rock fluid (liquid or gas) can find its way into the borehole, causing overpressure that can usually be reduced in a controlled manner. Alternatively, the borehole is sealed at the corresponding place deep underground. Secondly, when boring into a very liquid-permeable stratum or rock of very low strength. If this happens, some of the drilling fluid or cement may enter the surrounding rock. The drilling fluid is needed to bring the drilling dust to the surface and stabilise the borehole during the driving process. Once a section has been drilled, the borehole is lined with cemented pipe to keep it open in the long term. In most cases, though, stress changes only affect small rock volumes. So the probability of activating quite a large, pre-stressed fracture and thus triggering a fairly large, potentially noticeable earthquake is extremely low.

The Swiss Seismological Service (SED) at ETH Zurich does not normally recommend seismic monitoring in its Guide for Managing Induced Seismicity for deep boreholes (e.g. exploratory drilling). Nonetheless, to record evidence and clarify the distinction between natural and induced seismicity, it may make sense to install an additional monitoring station near a drill site. For this very purpose, to cite just one example, the SED is currently consolidating its network on behalf of Switzerland's National Cooperative for the Disposal of Radioactive Waste (Nagra) with a view to monitoring exploratory drilling in northeastern Switzerland.

2019-01-28

Earthquakes in Switzerland in 2018

Last year, the Swiss Seismological Service (SED) at ETH Zurich recorded more than 900 earthquakes with magnitudes of between -0.2 and 4.1 in Switzerland and its neighbouring countries. 25 of these quakes had a magnitude of 2.5 or more. Earthquakes of this size can usually be felt by the local population. So 2018 goes down as an average earthquake year, albeit one from which we can learn a lot. Because even very small quakes provide valuable information about the subsurface and thus make it easier to estimate future seismic activity.

Thanks to Switzerland's dense and highly sensitive earthquake measuring system, even the smallest quakes almost anywhere in Switzerland can be recorded and analysed. Earthquakes indicate the locations of more (or less) active faults today or over the years and provide insights into fracture processes deep beneath our feet. The seismic waves caused by earthquakes also offer data on the subsurface through which they pass. For example, the speed at which they travel tells something about the physical properties of the rock at the locations in question. These findings contribute towards more accurate risk assessment. So even 'quieter' earthquake years yield valuable knowledge.

The two strongest earthquakes felt over the largest areas by the Swiss population occurred on 17 January and 1 February 2018 in Austria's Kloster Valley (Montafon) near the Swiss border. Both quakes reached a magnitude of 4.1. The most powerful earthquake in Switzerland itself, with a magnitude of 3.2, occurred on 23 August near the twin-peaked mountain Dents de Morcles in the Canton of Valais. The SED received around 400 reports from people who felt this quake, mainly in the Rhone Valley, whose soft subsurface particularly intensified the shaking. Other earthquakes, some of which were also clearly felt, occurred on 15 and 16 May near Châtel-St-Denis in the Canton of Fribourg (with magnitudes of 3.1 and 2.9), on 3 November near Martigny in the Canton of Valais (magnitude 2.9) and on 29 December near Fribourg (magnitude 2.9). Only the quakes in the Kloster Valley ended up causing minor damage, such as cracks in buildings' façades.

In addition, last year saw the occurrence of some remarkable earthquake swarms. A swarm entails numerous quakes occurring over a fairly long period, without there being any clear sequence of foreshocks, mainshock and aftershocks. The most notable swarm involved a series of earthquakes northeast of St. Léonard, near Sion in the Canton of Valais. This sequence was related to a fault that has repeatedly been associated with phases of heightened seismic activity since 2014. It is believed to be part of the Rhone-Simplon fault, which appears to be broken into separate segments in this area. Another earthquake sequence worth mentioning occurred in the border area between Italy, France and Switzerland, in the east of the Mont Blanc Massif. Last year, the SED pinpointed the locations of close to 100 earthquakes with magnitudes between 0 and 2.2 in that area.

In general, in 2018, as in previous years, most earthquake activity occurred in the Valais region, the Canton of Graubünden and the areas along the Alpine front. Despite this concentration of seismic activity, historically it has been shown that no parts of Switzerland are earthquake-free regions. Based on the long-term average, a serious earthquake with a magnitude of 6 or more occurs in the earthquake country Switzerland every 50 to 150 years.

Download press release (PDF)

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2019-01-17

Experiment investigates how faulted rock retains CO2

Experiment investigates how faulted rock retains CO2

In order to achieve the ambitious UN climate targets, it is not enough to reduce greenhouse gas emissions. As a complementary option, one can capture CO2 directly from industrial production or from the atmosphere and store it permanently in the deep underground. For enabling so-called negative emissions, sequestrated CO2 needs to be safely retained for centuries. Once injected into a reservoir, CO2 may escape again in two ways: through existing boreholes or through existing faults in the rock above the reservoir meant to seal it. Faults in this caprock may not only influence the long-term containment of CO2. They are also the place, where earthquakes may occur.

Currently, the physical and chemical parameters governing leakage through faults, and the effects of rock deformation and chemical interactions leading to induced seismicity, are not fully understood. There is further limited knowledge on Swiss-specific conditions, making it difficult to judge to what extent underground CO2 storage could be an option in this country. This is why scientists from the Swiss Seismological Service at ETH Zurich and the SCCER-SoE are conducting an experiment, in collaboration with the Department of Mechanical and Process Engineering and the Institute of Geophysics at ETH Zurich as well as Swisstopo and EPFL. The experiment is taking place at the Mont Terri rock laboratory and part of the ELEGANCY project funded by the European Commission and the Swiss Federal Office of Energy.

Scientists will investigate how CO2 migrates withing a rock with faults, under what circumstances induced seismicity may occur, and how such a storage should be monitored best. Therefore, they will inject small amounts of CO2-enriched saltwater into a borehole that cuts through a small fault zone. To study how the fault zone reacts to the CO2 injected, they will observe the stability of the rock and analyse the coupling between fault slip, pore pressure, and fluid migration. Active and passive seismic sensors will monitor the variations of seismic velocities around the injection and register possible micro-earthquakes with magnitudes below zero.

In contrast to a full-scale CO2 storage project, this experiment only investigates the relevant processes with small amounts of CO2-enriched saltwater. Nonetheless, its findings will contribute to a better understanding of the relevant processes influencing the migration of CO2 in faults. Thereby, the experiment will also contribute to an enhanced site characterization. Worldwide, about twenty CO2 storage projects are already in operation, each sequestering up to three million tons of CO2 per year, and numerous plants are in the planning. In Switzerland, there is currently no CO2 storage project planned. 

Learn more about the ELEGANCY project:

www.sintef.no/elegancy/

www.sccer-soe.ch/research/pilots-demos/elegancy/

2018-12-29

Weak Earthquake near Fribourg

Weak Earthquake near Fribourg

On 29 December 2018 at 9:30 a weak earthquake with a magnitude of 2.9 was observed between Fribourg and Düdingen. The event was mainly felt in these two municipalities, but the Swiss Seismological Service at ETH Zurich also received felt reports also from other places within a radius of roughly 15 km. Damages are not expected due to such an event.

The region of Fribourg is well known for weak and shallow earthquakes. In the past numerous similar events were detected every year. However they are typically too weak to be felt by the public.

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 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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