On the evening of 18 March 2025 at approximately 6:45 p.m., a 4.1-magnitude earthquake shook Monaco and the Alpes-Maritimes region. The quake, with its epicentre located between the communes of Coaraze and Contes, was followed by a 3.8-magnitude aftershock at 10:25 p.m. Residents reported sensations similar to a train passing under their buildings or heavy objects being dropped by neighbours. Fortunately, no injuries or structural damages were reported. The Prefecture of the Alpes-Maritimes assured the public that there was zero tsunami risk.
Monaco is situated in a seismically active zone. The Principality has actively addressed this risk by implementing stringent building regulations. Since 1966, earthquake-resistant construction standards have been enforced, with significant updates introduced in a 2016 ministerial decree. These regulations incorporate “microzoning” to map seismic risk with greater precision across Monaco’s unique topography.
Strict construction regulations
In Monaco, unlike in France, building permits must be extremely detailed and include the entire structural plan, the main structural principles, with a calculation note from a design office justifying the structural choices based on risk. Modelling is performed to identify potential issues that could affect the building’s stability.
During construction, increased use of concrete and steel must be used with specific techniques, including the use of expansion joints. In a location with low seismic risk, expansion joints are 2 cm thick and are added every 40 to 50 metres. In Monaco, however, they are added every 25 metres, with a thickness of 4 to 6 cm. After construction is complete, an inspection takes place before a certificate is issued.
How to be prepared in the event of an Earthquake
Earthquakes are unpredictable and come without warning. The Prince’s Government recommends staying prepared in the event of another earthquake. Furniture and paintings should be securely attached to the walls. An emergency kit should be available with items like: a battery-powered radio, flashlight and first aid kit. Everyone in your household should learn how to turn off the electricity and gas.
If you are indoors during an earthquake, try to take cover under a sturdy desk or table, or against an interior wall and stay away from windows, fireplaces, and heavy objects. If you are outdoors, try to stay away from buildings. If driving, stop the vehicle and wait in your car until the shaking stops.
