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A 4.1 magnitude earthquake rocked Nice and the south-east of France last night, the most powerful quake in the region for 20 years.

Read more: 4.1 earthquake shakes Nice and surrounding areas: more tremors may come in aftermath

No significant damage was caused by the tremors – several of which appeared between successive earthquakes – however the region is known for experiencing several such events per year, increasing the overall risk of damage.

It is one of the areas most prone to earthquakes in mainland France due to its location close to the Alps.

Nice and the surrounding area is the largest city/metropolitan area facing this level of threat on mainland France.

The same risk level is faced throughout the Alps, parts of the east, and the Pyrénées mountain range, with other cities including Grenoble and Pau also at increased risk.

Paris and the surrounding areas as well as much of south-west France face the lowest level of risk.

A map below shows the risk levels. 

The information comes from the Ministry of Ecological Transition, which divides France into five categories of risk level. 

The highest – forte – is only given to some parts of the overseas departments of Martinique and Guadeloupe. 

This map has been in place since 2011, replacing a former version from 1991. 

The current version places 21,000 communes at some form of risk from earthquakes.

Despite the risk levels serious damage from earthquakes on the mainland are rare.

Several thousands are recorded each year but only a handful are noticed by humans. 

Recent significant earthquakes include: 

• 2019 - Teil, Ardèche: 5.4 magnitude

• 2003 - Saint-Dié, Vosges: 5.4

• 1996 - Annecy, Haute-Savoie: 5.2

The most powerful known earthquake in France occurred in 1799 in Vendée, causing thousands of buildings to be destroyed, yet no official deaths were recorded. It was estimated to have a magnitude of 6.4/6.5. 

Other powerful earthquakes in the Alpine regions have caused damage in French territory, including Europe’s strongest recorded earthquake near Basel, Switzerland in 1356.

Read more: Is France at risk of earthquakes? Where have powerful ones been recorded?