Earthquakes in Switzerland in 2012: a review

In 2012, the Swiss Seismological Service registered around 500 earthquakes in Switzerland and its neighboring countries. The magnitude of these earthquakes ranged between 0 and 4.2 on the Richter magnitude scale. Even though the strongest tremor was larger by one unit of magnitude than the strongest one from 2011, earthquake activity in Switzerland was relatively low in 2012. There were only 13 earthquakes with a magnitude of a minimum of 2.5 in comparison to an average of around 23 events over the past 37 years.

Five earthquakes were clearly felt by the population: among them were the two tremors in the region of Filisur on 1 and 2 January (magnitudes of 3.3 and 3.5), the two in Zug at the beginning of February (magnitudes of 4.2 and 3.5), as well as the single tremor in Vallorcine, between Martigny and Chamonix, at the end of October (magnitude of 3.6). The Filisur tremors were part of of a series of 10 tremors at the same location. The one from Vallorcine is part of ongoing seismic activity, which, in September 2005, recorded its most notable tremor to date, measuring 4.9 on the Richter magnitude scale. Generally speaking, the earthquakes in 2012 were concentrated in Valais and the canton of Graubünden, not unlike past years. Furthermore, increased activity was recorded for Central Switzerland.