In the beginning of February, the Swiss Seismological Service (SED) at ETH Zurich received a very special delivery: An 11-ton and 2.4 x 2.5 x 1 meters machine that can induce small earthquakes in palm-sized rock samples under conditions that are representative for the Earth’s crust in 4–8 km depth. This apparatus is called LabQuake and has been installed in the Rock Physics and Mechanics Laboratory under the responsibility of Dr. Claudio Madonna. LabQuake will enable a new research direction for the SED – Laboratory Seismology – aimed at gaining a better understanding of earthquake physics, for example in the context of induced earthquakes triggered by deep geothermal stimulations. Dr. Paul Selvadurai is leading the newly created Laboratory Seismology research group.

To develop a better understanding of nature, scientist often examine complex problems in the laboratory where they control the environment, repeat experiments and place dense arrays of sensors. With LabQuake, scientists induce tens of thousands of very small earthquakes – so-called nano-seismic events that produce the same order of energy as an insect flapping its wings once – in rock samples and observe how they form, what controls them, and why they cease. To this end, LabQuake is equipped with various sensors, measuring in great detail the evolution of nano-seismicity, strain and pore-pressure within the rock sample.

Last year, twice as many earthquakes occurred in Switzerland and in neighbouring countries compared to the long-term average. For nearly 50 of the total of 1,670 recorded earthquakes, the Swiss Seismological Service (SED) at ETH Zurich received five or more felt reports. Most of the quakes can be attributed to five active earthquake sequences that shaped seismic activity in 2019. One of them was in the canton of Valais, in the area between Anzère and the Sanetsch Pass. The other four occurred just over the Swiss border, at Courmayeur (Italy), Novel (France), Konstanz (Germany) and Chamonix (France).

In Switzerland, earthquakes often occur in sequences referred to as 'earthquake swarms', i.e. clusters of tremors occurring over time at one, specific location. An unusual feature of last year's seismic activity was the number of highly active earthquake sequences leading to a never previously recorded amount of events since modern seismic monitoring began in the 1970s. This also resulted in more felt earthquakes than usual. As a rule, quakes felt by humans have usually a magnitude of 2.5 or more. The last time a similar cluster of felt quakes occurred was back in 1964, when Sarnen, in the canton of Obwalden, experienced a distinct sequence of earthquakes over a period of several months, with magnitudes of up to 5.3. Although such a high level of earthquake activity as that experienced in 2019 is rare, it is neither unexpected, nor a sign of an increased seismic hazard over the months and years to come.

One memorable event of the past year was undoubtedly the earthquake swarm that occurred north of Sion in Valais in November. So that was the inspiration for this year's Christmas card. The baubles on the Christmas tree represent the numerous quakes of the swarm, and the mountain range behind it represents the cumulative number of tremors. Click on the impage for a detailed view.

The Sion earthquake swarm took place in a region historically known for its seismic activity and where numerous small and occasionally larger quakes can also be expected in the future. There is no way of predicting exactly how seismic activity will develop there, but analysing the extensive data provided by this earthquake swarm is helping us gain a clearer understanding of earthquake activity in the area.

We wish you a very Merry Christmas and a happy and instructive New Year!

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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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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