Type Oceanographic cruise
Set This cruise is part of the set MOMARSAT : MONITORING THE MID ATLANTIC RIDGE
Ship L'Atalante
Ship owner Ifremer
Dates 11/07/2023 - 29/07/2023
Chief scientist(s) MATABOS Marjolaine ORCID


Centre Ifremer Bretagne

ZI Pointe du Diable

CS 10070

29280 Plouzané

+33 (0)2

DOI 10.17600/18002419

The MoMARSAT campaign series provides annual maintenance for the EMSO-Açores observatory on the Lucky Strike hydrothermal field. This seafloor observatory has been in operation since 2010 and aims to acquire time series on hydrothermal, tectonic and volcanic processes and ecosystems at an active hydrothermal site on the Mid-Atlantic Ridge. It is part of the EMSO (European Multidiciplinary Seafloor and water column Observatory-ERIC) network, supported in France by the EMSO-FR Research Infrastructure (MESR) and managed by an Ifremer-CNRS collaboration.

The observatory infrastructure includes a surface buoy (BOREL) that ensures data transferto a server on land and communication with the connected instruments, and two seafloor monitoring stations (SEAMON) that provide power and communication via to instruments deployed on the seafloor and communicate acoustically with the surface buoy. The BOREL buoy is also instrumented with a weather station, a geodetic GPS and an automatic identification system (AIS). The first observation station (SEAMON West) is deployed at the center of the fossil lava lake characteristic of the Lucky Strike hydrothermal field, and is dedicated to geophysical studies and monitoring essential ocean variables (EOVs). It connects an Ocean Bottom Seismometer (OBS), a permanent pressure gauge (JPP) and the EGIM European generic instrumentation module equipped with a CTD, hydrophone, optode, turbidimeter and ADCP. The second station (SEAMON EST) is deployed at the base of the active edifice Tour Eiffel and support the study of the interactions between hydrothermal circulation, physico-chemical factors and fauna dynamics at the edifice scale. Seamon East is equipped with a biological observation module (TEMPO- with HDTV camera and 4 projectors, temperature, oxygen and dissolved iron sensors), an autonomous sequential hydrothermal fluid sampler (DEAFS), a network of 4 hydrophones (HYDROCTOPUS), a turbidimeter and a dissolved oxygen and temperature sensor.

The observational array also includes autonomous instruments that store data internally: 4 OBS, 2 permanent pressure gauges (JPP), 36 autonomous temperature probes for hydrothermal fluids and mixing zones, 7 autonomous bottom current meters, 6 biological and microbiological colonizers, and an oceanographic mooring. In situ measurements as well as fluid and biological sampling and colonization / recolonization experiments are carried out to complete the set of parameters and integrate a spatial component into each maintenance operation.

Maintenance operations included the recovery of the BOREL-SEAMON infrastructure and their connected instruments, onboard reconditioning, and the redeployment of the stations. The recovery and deployment of autonomous instruments, in situ measurements and sampling were performed during ROV dives.

The study area is part of Portugal's EEZ and an OSPAR Marine Protected Area.

Published data

Chavagnac Valérie, Destrigneville Christine, Castillo Alain (2023). Geochemistry of hydrothermal fluids at the Lucky Strike Hydrothermal Field data from the EMSO-Azores observatory, 2023.

Lemaréchal Cyprien, Leizour Stephane, Hamon Michel, Matabos Marjolaine (2023). CTD and ADCP hydrothermal plume data from the MomarSat 2023 cruise.

Lemaréchal Cyprien, Ferron Bruno, Leizour Stephane, Hamon Michel, Sarradin Pierre-Marie, Matabos Marjolaine (2023). Lucky Strike, EMSO-Azores observatory : mooring 2023 dataset.

Data managed by SISMER

Sampling operations




References of Technical Reports

Matabos MarjolaineORCID (2023). Compte-rendu opérationnel de la campagne MOMARSAT 2023. Zone de travail Lucky Strike. Infrastructure de Recherche EMSO AÇORES. Navire L'ATALANTE, Submersible VICTOR6000.

Besson Florian (coord.)ORCID, Chu Nan-Chin, Le Gall Morgane, Sarradin Pierre-MarieORCID, Ybert Sebastien (2023). Rapport de veille scientifique et technologique relative aux ressources minérales non énergétiques des grands fonds. Convention référence 19/1000 085-AV1 entre le Ministère de la Transition Écologique – Direction de l’Eau et de la Biodiversité et l’Institut français de recherche pour l’exploitation de la mer – Action 5. 2. REM/2023-015. Rapport de veille scientifique n°16.

Cotten Clemence, Sarrazin JozeeORCID (2022). Data management plan. DEEP-REST: Conservation and restoration of deep-sea ecosystems in the context of deep-sea mining. Deliverable D1.2.