Specific action SMM – Mobile marine seismology

Scope

Seismological and environmental observation in the marine environment using acoustic and seismological sensors uses instruments on the seabed, drifting or on moorings, deployed from oceanographic vessels or ships of opportunity. This instrumentation enables temporary to semi-temporary observation of seismic and/or volcanic activity at the land/sea interface or in the open ocean. It can be used to image the lithosphere, track deformations using geodesy methods, and conduct environmental seismology programs.

Until 2022, three independent marine mobile seismology fleets existed in France: INSU/IPGP (CNRS/IPGP) – based in Paris, Géoazur (CNRS/IRD/OCA) – based in Nice, and Ifremer/Geo-Ocean – (Ifremer/CNRS/UBO) based in Brest.

To optimize acquisition and maintenance costs, coordinate equipment deployment and ensure greater visibility of marine seismological actions, these three fleets have been brought together in 2023 within a specific Marine Mobile Seismology Action, attached to the Epos-France Seismology Thematic Group. This action is also part of the PIA3-EquipEx+ Marmor project (Marine Advanced geophysical Research equipment and Mayotte multidisciplinary Observatory for research and Response), which has a budget of €15.4 million over 8 years.

With regard to the National Instrumented Park and the Rapid Response Park, the SMM Specific Action is responsible for managing requests for the use of instruments, the evolution and maintenance of the park, the harmonization of instruments and their use, quality control and the management of field missions.

For the rapid response fleet, the Action is also responsible for managing and maintaining a fleet of dedicated instruments, always available and operational to respond to a seismic crisis and intervene as quickly as possible. It also coordinates with Epos-France’s national fleet of Sismob mobile seismometers for land/sea deployments.

Objectives

The objectives of the AS SMM are to :

• federate the French scientific community using SMM;
• offer French researchers access to a range of instruments suited to high-quality scientific research;
• archive data from these instruments in the Epos-France data center;
• ensure that the technical teams involved in data acquisition are cited;
• extend the Epos-France database to other types of marine instruments by creating data and metadata adapted to the Epos-France seismological data center;
• ensure that the infrastructure meets the needs of the scientific community.