Comoros Archipelago Seismic and Volcano Network

The Mayotte volcanological and seismological monitoring network (REVOSIMA) was created in response to the sub-marine eruption that started in May 2018. Composed by IPGP, BRGM, IFREMER and CNRS, its main missions are 1) to observe and study volcanic phenomena through real-time volcano monitoring, 2) to conduct research programs, and 3) to communicate, disseminate and inform authorities and civil society. These real-time observations and research can contribute to the prevention, and mitigation of seismic and volcanic risks. The main objective is to collect geological, geophysical and geochemical data over long periods of time to improve the understanding and modeling of volcanic processes at active volcanoes, to allow the systematic elaboration of long-term multi-parameters databases available to the scientific community, and to inform the authorities in charge of civil protection of any change in the volcano activity and after periods of local and regionally felt earthquakes. These missions can be done thanks to the QM network. The permanent QM network is composed of stations geographically distributed mainly on Mayotte Island, and on a broader extension on Grande Glorieuse Island and on other islands of the Comoros archipelago. The stations all share the following features: (1) power: solar panels and battery, or sometimes national electricity company, (2) telemetry: wifi, 4G, or internet link, and (3) sensors: seismometers Ground sensors are well coupled with the ground, and the environmental insulation is ensured by insulating foil and plastic box, or by installation in natural or anthropic vaults, or inside boreholes. Most of the time, sensors are separated from the electronics in order to avoid any electric, magnetic and thermal mutual influence. Seismometers are broadband Nanometrics Trillium Compact posthole 120s or Trillium120 posthole. All data are disseminated in miniSEED and stationXML FDSN formats. Seismic data of this network are disseminated both in real time (raw data) and after validation. The permanent network is completed since 2019 by land stations and OBS deployments under the temporary network code 1T with data available from Résif.