Speaking to 24 Heures, Raphaël Mayoraz, geologist for the canton of Valais, said the Swiss “tend to forget” that Switzerland has experienced earthquakes of magnitude 6 and above in the past.
“In the Valais earthquakes of magnitude 6 and above on the Richter scale occur about once every 100 years,” he said.
The last time was in 1946 when a quake of 6.1 hit Sierre; before that Visp experienced a 6.2 magnitude earthquake in 1855.
“We therefore expect another major earthquake by 2040,” Mayoraz told the paper.
He was speaking following the tragedy in Italy on Wednesday morning when a 6.2 magnitude quake destroyed several mountains villages, killing 247 and leaving many more still trapped under the rubble.
Earthquakes in Switzerland 1975-2012 plus the ten largest ever recorded. Source: SED
Around 500-800 earthquakes are registered every year in Switzerland, according to the federal environment office (BAFU).
They are recorded by the Swiss Seismological Service (SED) on its website.
Most are so light that they won’t be felt, but around five percent are, such as a quake of 3.3 which hit Sion in the Valais on June 24th this year.
According to the SED, strong earthquakes are a possibility in Switzerland, with the cantons of Valais, Basel and Graubünden being the most affected by seismic activity.
The country’s strongest documented earthquake, of 6.6 on the Richter scale, hit Basel in 1356.
Around ten earthquakes of between 3 and 4 magnitude hit the country every year, while strong earthquakes, classified of 6 magnitude or above, occur once every 50-150 years, it said.
Earthquake preparedness started in the 1990s in Switzerland, particularly in relation to building guidelines.
Since the latest building codes were released in 2003 “some progress” has been made but “much remains to be done in the private sector to achieve the consistent integration of seismic safety into building projects,” says BAFU on its website.
Cantonal governments have much of the responsibilty for ensuring earthquake preparedness.
According to geologist Mayoraz, new buildings in the Valais have been earthquake-ready since a new law on the matter came into force in 2004, and earthquake education measures are in place, but the canton “is not there yet, so I hope the earthquake will wait a bit longer before arriving”, he told 24 Heures.