Seismic Movements – Earthquake Country Switzerland – You Should Know It – News

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At the weekend, the ground shook noticeably in many places in this country. This is not uncommon – an overview.

Is Switzerland an “earthquake hotspot”? When it comes to earthquakes, the first thing that comes to mind is the outside. A 6.8-magnitude earthquake in China killed 93 people last week, and a 7.6-magnitude earthquake shook Papua New Guinea on Sunday. But Switzerland is not immune to shocks either. The earth shook, Saturday evening, near Mulhouse (Fr) near Basel. According to the Swiss Seismological Service at ETH Zurich (SED), a 4.7 magnitude earthquake was felt in large parts of Switzerland.

On Sunday there were aftershocks of magnitude 3.1 near Basel – and in Liechtenstein Vaduz The earth shook on September 1st as the state parliament was debating earthquake insurance. Coincidence, or is Switzerland an “earthquake epicenter” more than expected? Both are true, as ETH seismologist Philip Roth asserts: “On the one hand, these are cyclical fluctuations. On the other hand, Switzerland is an earthquake country. In a European comparison, we have a relatively high number of earthquakes, albeit far fewer than in high-risk areas such as Italy or Greece.”

Caption:

A view of the earthquakes recorded in Switzerland in the last 90 days. Earthquakes observed near Mulhouse (F) and Vaduz at the beginning of September as well as other observed earthquakes in Valais, including on 10 September in Orsier, are indicated in red.

Screenshot of the Swiss Seismological Service (SED)

Are more aftershocks expected? We expect more aftershocks in the Basel region in the next few days to weeks. There could be another noticeable earthquake underneath. A larger earthquake also cannot be ruled out, but the probability of it happening is small,” explains the seismologist. According to the SED, earthquakes in the Basel region are nothing unusual, with a magnitude 4.7 earthquake occurring only every 10 to 20 years.

How do earthquakes form?


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The vast majority of earthquakes are called “tectonic earthquakes”. It is formed by the plates of the earth’s outer layer, which move a few centimeters per year. Friction or bending of these plates results in stresses being discharged into the earthquake fracture. Most earthquakes are too weak to be felt by humans.

Earthquakes happen loudly in Switzerland pavo By the large-scale continental movements of Africa and Europe. When the African plate collides with the Eurasian plate, stresses build up in the earth’s crust, which then set off in the form of earthquakes.

Are earthquakes increasing in this country? The Earthquake Service records three to four earthquakes per day in Switzerland and neighboring countries. That’s the equivalent of 1,000 to 1,500 earthquakes per year. However, only 10 to 20 of them with values ​​of 2.5 can be felt by humans. In 2021, ETH recorded 32 notable earthquakes. It is conceivable that there will be an accumulation of observed earthquakes this year, but that will not be statistically significant in the long run. Here, too, seismologist Philip Roth talks about natural fluctuations, for unknown reasons.

Where in Switzerland does the earth tremble the most? According to the SED, earthquakes can occur basically anywhere. The probability is highest in Valais, followed by the Basel region. But the St. Gallen valley, central Switzerland and Graubünden are also considered critically endangered areas.

Map with Swiss seismic zones.

Caption:

Switzerland’s five earthquake regions: Valais (red/orange) is particularly vulnerable, followed by Basel (orange). The probability of an earthquake is also slightly higher in Engadin, in parts of central Switzerland, in the Bernese Oberland and the St. Gallen-Rhine valley (yellow).

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Is the nuclear warehouse earthquake-resistant? People felt the weekend earthquake in Nordlich Lagern (ZH), where a new nuclear waste repository will be built. Nagra chief Matthias Braun confirmed in one an interviewSeismic safety has been taken into account when selecting a site. Felix Altorfer of the Nuclear Regulatory Authority in Insei added to the media that earthquakes are especially noticeable above the Earth’s surface. The damage on the surface is much greater than in the depth of the warehouse.

What major earthquakes have occurred in Switzerland? A devastating earthquake of magnitude 6 or greater occurs approximately every 50 to 150 years. The last time such an event occurred in Valais was in 1946. At that time, a 5.8-magnitude earthquake hit the Sierre region.

According to the SED, 12 documented earthquakes with significant damage have occurred in Switzerland since the 13th century. In addition to the aforementioned earthquake in Sierre in 1946, a series of earthquakes in canton Obwalden in 1964 (magnitude 5.3) caused damage. The strongest earthquake in Switzerland to date occurred in Basel in 1356, with a magnitude of 6.6.

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