Bringing the Ocean to Society
27 Oct 2020
Celebrating 10 years of deep-sea observation
EurOcean Member Ifremer continues to study the marine geological and geochemical phenomena caused by the slow separation of tectonic plates.

Similar to a space station, in 2010 the EMSO Azores scientific observatory was deployed 1700 m onto underwater mountain ranges and volcanos in the middle of the Atlantic Ocean. Only 4 observatories of its kind exist in the world. Continuous observation over the last 10 years has made it possible to advance knowledge about the remarkable biodiversity, volcanism and hydrothermal circulation in deep marine environments. The oceanographic vessel Pourquoi Pas ? (Why not?) has been stationed since 13th September to conduct the annual maintenance of this battery of technologies (Momarsat campaign, coordinated by Ifremer and the CNRS).

The depths of the ocean are our planet’s final frontier; we know less about them than we do about the moon’s surface! With plains, canyons, volcanic arcs, they are made up of varied landscapes, and sometimes home to rich fauna.

Faced with this gap in scientific knowledge, the scientific observatory EMSO Açores (European multidisciplinary seafloor and water column observatorywas deployed on a volcano, on the boundaries of the African and North American tectonic plates. Most of the instruments are concentrated across a 1 km2 surface area. A 400m-diameter lake of lava is located at the centre surrounded by active hydrothermal vents which stand at up to 15 metres tall spewing black liquids (due to the high metal concentration) at temperatures of more than 300°C.

The deep sea, just a click away

The observatory allows for real-time monitoring of this ecosystem, with a fundamental research objective. ‘We can witness, first hand, the secrets of how our planet works’, explains Pierre-Marie Sarradin, head of the deep-sea environment unit at Ifremer and the Momarsat mission lead. “Thanks to this observatory, we can get a better understanding of the geological and geochemical phenomena caused by the slow separation of plates and the development of life so far away from sunlight."

Two autonomous stations equipped with cameras and several sensors acoustically transmit data to a buoy located on the surface of the ocean. The buoy is programmed to transmit the data, by satellite, to Brest every six hours.

Such a structure requires annual maintenance; for example, to change the batteries in electronic devices or to change sensors. In order to do this, an oceanographic campaign, named Momarsat, takes place every summer. The 2020 edition is currently underway until October 4 onboard the Pourquoi Pas? with sanitary conditions adapted to the Covid context. Beyond conducting maintenance, scientists also collect other data through fluid, rock and animal sampling, as well as 3D video surveys of the area using the remote-controlled submarine Victor 6000.

Original news article on Ifremer's website.