The Momarsat 2022 cruise is under way! Taking place on 6-27 June 2022 and journeying to the northern Mid-Atlantic Ridge, the expedition will carry out the yearly maintenance of the EMSO-Azores observatory. A team of 30 scientists from Ifremer, CNRS (IPGP, GET, MIO, LPO), University of Western Brittany (UBO) and University of the Azores are on board the French research vessel Pourquoi pas? heading in the direction of the Lucky Strike vent field off the Azores. The French manned submersible Nautile will be used to oversee all operations on the seafloor. The multidisciplinary scientific team is composed of 13 researchers, PhD and Master students as well as 15 engineers and technicians – collectively they will ensure the maintenance and continued smooth running of the observatory, its autonomous sensors and associated sampling programme. This year, the team invited an artist along who will, throughout the cruise, capture the ship’s activities through a number of sketches and illustrations.
EMSO-Azores is a non-cabled multidisciplinary observatory dedicated to the long-term integrated study of mid-ocean ridge processes, from the sub-seafloor to the water column, from geophysics to biological responses. The observatory is composed of two SEAMON (Sea Monitoring Nodes) stations and a surface buoy Borel. The first station – SEAMON west – is dedicated to geophysical studies. It is located in a fossil lava lake, away from hydrothermal vents and connects a bottom seismometer (OBS), a permanent pressure gauge and a European Generic module (EGIM) equipped with CTD, optode, hydrophone, turbidity meter, tsunami pressure sensor and ADCP. This EGIM allows long-term monitoring of background seawater dynamics. The second station – SEAMON East – is located at the base of the active Tour Eiffel hydrothermal edifice. It provides power and communication to a high-resolution video camera with two LED projectors (TEMPO), an instrumented microbial coloniser (CISICS), turbidity meter, optode and a prototype fluid sampler DEAFS that sequentially collects end-member fluids from a bell deployed directly on a black smoker. A surface buoy – BOREL – ensures data transfer between the two bottom stations and the Ifremer headquarters in Brest, and is equipped with a geodesic GPS and a meteorological station. During the year, a satellite link allows data transmission to land every 6 hours. During this cruise, the two stations and the surface buoy will be recovered and redeployed after reconditioning on board. Scientists are eager to see their data and learn all about events that occurred at the site over the year!
Repeated in situ collection of fauna, fluids and rocks, as well as measurement of a number of parameters will complement the temporal monitoring of the vent sites while extending the spatial extent of our studies. Some experimental studies will also be carry out to evaluate carbon transfer between the different faunal species associated with vent mussel communities.
To complement this multidisciplinary and interdisciplinary approach, a team of physical oceanographers will deploy Microryo, a new mooring dedicated to the study of local microstructure turbulences and perform, in between dives, several vertical profiles using a Vertical Microstructure Profilers (VMP) and CTD.
We also have at heart to share our experience at sea and raise awareness. A Facebook page for the general public will be active during the entire cruise and the drawings from our sketcher Damien Roudeau will be posted daily on Instagram (@Momarsat).