Small Earthquakes near Diemtigen BE

In the early morning of 10. Mai 2014, at 3:45 a.m., a small earthquake of Magnitude 2.7 rattled the Niedersimmental and the region Thun / Spiez. The earthquake occurred at approximately 10 km depth near Diemtigen (BE), and was lightly felt within a radius of around 15 km.

This event is the strongest so far of a swarm of small earthquakes that commenced on 13. April of this year. Shortly before and after this earthquake another four microearthquakes occurred with magnitudes between 1 and 1.7. In total the SED registered around 60 events since the beginning of that swarm, all of them within an area of a few km and at a depth near 10 km.

In so-called earthquake swarms numerous events occur over an extended period of time without a clear succession of foreshock, mainshock, aftershock. Earthquake swarms are well-known phenomena globally and also in Switzerland. Between 16 and 18 April, for example, a sequence of more than 30 small events occurred near Frauenfeld (TG).

Usually this swarm-activity terminates after a few weeks or months, in rare cases the earthquakes become stronger and more frequent with time. The development of an earthquake swarm is equally unpredictable as the occurrence of earthquakes in general.

In Switzerland, earthquakes that are strong enough to cause damage can in principle happen anywhere anytime. On average, however, an earthquake of magnitude 6 or more happens only once in 50 to 150 years. The annual probability of such an earthquake in Switzerland is thus approximately 1 percent.