New Insights into Mayotte’s Ongoing Earthquake Swarm

Since May 2018, Mayotte, a French overseas territory in the Indian Ocean, has experienced a series of seismic events, including hundreds of earthquakes. The most significant of these occurred on May 15, 2018, when a magnitude 5.8 earthquake struck approximately 50 km offshore, marking the largest quake ever recorded in the Comoros basin. While these tremors have not caused major damage, they have raised concerns and prompted scientific investigations.

The epicenter of the seismic activity is located beneath the sea, within a zone about 20 km in diameter east of Mamoudzou. Seismic events of magnitude 4 and above have been felt on the island, while smaller quakes have been detected by monitoring networks. Notably, the depth of these earthquakes has not been precisely determined due to limitations in the current observation network.

In response to this ongoing seismic activity, BRGM (French Geological Survey) has been actively involved in monitoring and researching the phenomenon. Collaborating with other scientific institutions, BRGM has established the REVOSIMA network to observe and analyze the seismic and volcanic activities in the region. This network has been instrumental in tracking the progression of the earthquake swarm and understanding its underlying causes.

While the exact mechanisms driving this earthquake swarm remain under investigation, BRGM continues to monitor the situation closely. The data collected will be crucial in assessing potential risks and informing future preparedness strategies for Mayotte and the surrounding regions.