What is the worst natural disaster you could ever experience? If your answer is an earthquake, you are correct. But the question of whether you should worry about an earthquake in Switzerland isn’t so easily answered. For help, let’s look at Switzerland’s seismic events in the past and present.
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Are Earthquakes Common in Switzerland?
Earthquakes are common in countries that sit on a fault line. Switzerland sits on top of several significant fault lines, so it is at high risk for earthquakes. In fact, the rumbling beneath the earth is responsible for the beautiful, towering Alps. To this day, the earth beneath the Alpine country quakes at least twice a day or around 800 times per year!
Fortunately, (so far) these numerous earthquakes are rarely severe. This is good news since a major earthquake with a magnitude of 6 or greater does immense damage. At this time, only around 10 percent of those 800 quakes are felt.
The people of Switzerland feel between 10 and 20 quakes in a year. These earthquakes have a magnitude of 2.5 or higher. The long-term average of a magnitude 2.5 or higher earthquake in Switzerland is 23 per year. The Swiss have about a one percent chance of experiencing a catastrophic magnitude 6 or higher within the next year. And one of that magnitude can be expected every 50 to 150 years.
The region in Switzerland at the highest risk is the mountainous canton of Valais. The next highest-risk areas include Basel, Graubünden, the St. Gallen Rhine Valley, and central Switzerland respectively.
Major Earthquakes in Switzerland
Let’s begin with the largest earthquake in Swiss recorded history. It happened in Basel all the way back in 1356 and was a magnitude 6.6. Basel lies within the Rhine rift valley on a fault line running from the North Sea to Switzerland. That year, the earth’s crust gaped open when the fault fractured.
The last significant earthquake in Switzerland occurred in 1991 in Vaz in the canton of Grisons and was a magnitude 5.0.
Another earthquake of that strength happened in 1946 in the canton of Valais near Sierre. Before that, a serious earthquake occurred in 1855 in Visp-Stalden. Sierra also had a 6.1-magnitude earthquake in 1755. And at the turn of the 17th century, the village of Unterwalden experienced a 6.2 earthquake.
How Ready Is Switzerland for Earthquakes?
Catastrophic earthquakes in Switzerland are few and far between. The danger is that this may give the Swiss a false sense of security. What they must realize is every region in the country has some degree of seismic activity. In 2021, Switzerland and the surrounding region experienced more than 1,100 tremors. That same year, there were more with a magnitude between 2.5 and 4.1 than the long-term average. Three magnitude 4 or greater earthquakes also happened in 2021. They occurred at the Furka pass on July 1st, in Arolla on October 5th, and in Ajoie in the Juras on Christmas Day.
The Swiss can expect at least a magnitude 5 earthquake every 8 to 15 years and a magnitude of 6 every 100 years. One as severe as the earthquake near Basel in 1356 could claim as many as 2,000 lives and cause enormous damage to buildings, houses, bridges, and streets. The damage to buildings, furnishings, and fixtures could cost as much as 50 to 100 billion francs. This translates to roughly one-thousandths of the value of all buildings and infrastructure in Switzerland. This could mean mandatory earthquake insurance for Swiss citizens to make up for the deficit.
The risk of a catastrophic earthquake in Switzerland is greatest for residents in Wallis and Basel. This is followed by Engadin, Mittelbünden, the St. Gallen Rhine Valley, and central Switzerland.
The Eurasian and African plates continue to push together, so everyone should stay ready for “the Big One.”
Courtesy of Wikimedia for the image header.