From 16 to 30 September 2019, the number of earthquakes and their intensity is similar to that recorded during the first half of September (506), according to the 5th REVOSIMA bulletin, the Mayotte Volcanological and Seismological Monitoring Network, which is based on data from shore-based measurement stations.
If the magnitudes did not exceed 3.6, there were 676 earthquakes in 2 weeks, or 19 per day. Seismic activity is therefore “globally stable” over the last few weeks, REVOSIMA analyses, but
“nevertheless important, and (which) testifies to an ever-increasing volcanic activity. »
The phenomenon itself has not evolved, with an underwater volcanic eruption underway 50-60 km east of Mayotte and a main seismic activity still concentrated 5-15 km from Petite-Terre, at depths of 19-50 km.
Lower seismicity in number and energy (low magnitude between 1 and 3), also always recorded near Petite-Terre about 5 km to the east (at depths of 20-50 km) or even under Petite Terre. This seismicity was already visible on seabed seismometer data since February 2019. Apart from possible other underwater emissions, but to be confirmed, the situation remains almost the same.