Earthquakes in Basel

Did you feel the earthquake that hit the Basel region this past Saturday (September 10), at around 18:00? It was one of the stronger rumbles measured here in recent years, registering at 4.7 on the Richter scale, and its epicenter was located between Basel and Mulhouse in France.

Earthquakes are by no means rare in the Basel region, but only few are strong enough to be felt by people. The main reason for earthquakes to occur in this region is believed to be the geological structure of the Oberer Rheingraben (upper Rhine fault), an old rift system that is oriented northeast to southwest and whose southern end lies in the Basel region. It makes the Basel area the region with the second-highest seismic activity in Switzerland, after Valais. The most infamous example is the the earthquake that hit the Basel region on October 18, 1356, with an estimated magnitude of at least 6.6 on the Richter scale. It caused severe damage in the region and killed hundreds of people. Much of Basel was destroyed, either by the earthquake itself or the resulting fires, and large sections of the Münster, which already existed at that time, caved in.

Overall, the Swiss Seismological Service at ETH Zürich, with its nation-wide network of seismometers, records 1,000-1,500 earthquakes per year in Switzerland. But only about 10-20 of them are strong enough to be felt by citizens. And the Service estimates that the likelihood of an earthquake with a magnitude of 6 or more is only 1% within any given year. The map at the top shows the instrumental recorded earthquakes in Switzerland between 1975 and 2017 with a magnitude of at least 2.0 on the Richter scale.

If you want to learn more about earthquakes in Basel and Switzerland, how you can prepare, and what you should do in case a stronger earthquake does occur, download the article below, which was published in Basel Life Magazine in October 2019.