Initial assessment of MAYOBS 13 campaigns
INTERMINISTERIAL PRESS RELEASE 04/06/2020 - Successful marine campaigns to monitor seismo-volcanic phenomena off Mayotte
Publication date: 04/06/2020
Observatories, Press, Research
Related observatories : Volcanological and Seismological Monitoring Network of Mayotte (REVOSIMA)
Related themes : Natural Hazards
Élisabeth BORNE, Minister for the Ecological Transition and Solidarity, Frédérique VIDAL, Minister for Higher Education, Research and Innovation, Annick GIRARDIN, Minister for Overseas France, and Florence PARLY, Minister for the Armed Forces, are delighted with the success of the oceanographic observation missions of the seismo-volcanic phenomenon in Mayotte, which were carried out despite the constraints imposed by the health crisis we are experiencing. The campaigns carried out as part of the dedicated monitoring network (REVOSIMA) set up in 2019 under the coordination of the Interministerial Delegation for Major Overseas Risks, are therefore continuing to provide all the information needed to protect the population of Mayotte.
An initial oceanographic campaign (MAYOBS 13-2) took place on the Fugro vessel Gauss from May 4th to 11th 2020, remotely operated by IFREMER, IPGP, BRGM and CNRS. It was used to acquire seabed surveys and images of the water column over an area of around 1,500 km² to the east of the island of Mayotte.
Surveys of the seabed have already shown that the morphology of the volcano discovered in May 2019 around 50 km to the east of the coast of Mayotte has not changed significantly since last August.
However, the relief of the seabed in this area (known as the volcano zone) has changed over a sector of around 5 km2 to the north-west of the volcano. This change could be the result of new magma flows, the thickness, extent and volume of which are currently being assessed.
They indicate the persistence of volcanic activity, as well as the identification of two new plumes of hot fluids* at a depth of 1,400 m in the vicinity of the earthquake generation zones (seismic swarm).
These observations were supplemented by a second campaign (Mayobs 13-1), which was carried out from 6 to 19 May 2020, aboard the French Navy’s overseas support and assistance vessel Champlain. The data from the seabed seismometers recovered during this campaign are vital for refining our knowledge of seismic phenomena, which are continuously monitored by networks of seismographs on land. The data collected, which covers a period of several months, will be processed and made available to the public at the end of June. Reconditioned seismometers have been immersed for a new series of measurements lasting around 6 months.
The ministers would like to thank all the scientists, engineers, technicians and administrative staff who have worked under difficult conditions to bring this scientific campaign to a successful conclusion and make an active contribution to the Government’s commitment to protecting the people of Mayotte.
- The preliminary results of the Mayobs 13-2 campaign are available on the REVOSIMA page.
- See the press release on the Préfecture de Mayotte website
*Contrary to what has been mentioned in this press release, no temperature measurements were taken during this campaign.
