Specific action Marine mobile seismology (SMM)

Birth of the park

Seismological and environmental observation in the marine domain by acoustic and seismological sensors uses instruments on the sea floor, drifting or on moorings, deployed from oceanographic vessels or ships of opportunity. This instrumentation allows temporary to semi-temporary observation of seismic and/or volcanic activity at the land/sea interface or in the open ocean. It allows to image the Earth, to follow its seismological activity, to follow deformations thanks to geodesy methods and to conduct environmental seismology programs.

Until 2022, three independent fleets of ocean bottom seismometers (OBS) existed in France: INSU/IPGP (CNRS/IPGP) – hosted in Paris, Géoazur (CNRS/IRD/OCA) – hosted in Nice, and Ifremer/Geo-Ocean (Ifremer/CNRS/UBO) – hosted in Brest. Due to the specific constraints of OBS recordings, very little data from these parks arrived at the Résif Seismological Data Center.

To optimize acquisition and maintenance costs, coordinate the implementation of equipment, and ensure greater visibility of marine seismological actions, Résif, the French Seismological and Geodetic Network, requested in 2017 that the INSU/IPGP and Geoazur OBS fleets be combined into a single national fleet. At the same time, a specific OBS data preparation/validation A-node was created. Subsequently, the Ifremer/Geo-Ocean pole wished to get involved in this grouping and add hydroacoustic monitoring by hydrophone networks. Thus, it was decided to create a Specific Action Resif Mobile Marine Seismology (SMM), covering the instrumental park and the node A.

In addition, in February 2021, the ANR (PIA3-ESR-Equipex+) decided to fund the MARMOR project, one of the objectives of which is to structure the French scientific community, by providing the underwater seismology and geodesy equipment necessary to conduct excellent research in the oceans. This allows the park to offer instruments that are better adapted to current needs, including those required for rapid response to seismic and volcanic crises.

The SMM data are handled by the SMM node A of the Résif information system, managed by the Institut de Physique du Globe de Paris.

Main objectives of the Mobile Marine Seismology specific action

Federate the French scientific community using MMS;
To provide French researchers with access to a range of instruments suitable for quality scientific research (including rapid response) through a single access/request portal.
To archive the data acquired by the instruments of the park and their metadata in the EPOS-France data center in order to guarantee their durability and to make them available to the national and international community.

Contacts :

• OCA/ Géoazur : A. Galve and D. Oregioni
• IPGP / INSU : W. Crawford and R. Daniel
• Ifremer / Geo-Ocean : S. Bazin and P. Pelleau