Sophie Cravatte first worked on the dynamics of the equatorial ocean in relation to the El Niño and La Niña climate phenomena, before turning her attention to the tropical Pacific Ocean and marine heatwaves.
“Women oceanographers (4/12). They have made the ocean their object of study, sometimes even their main concern.Physicists, chemists, geologists or biologists, they all contribute to improving our knowledge of the marine environment. océans connectés goes to meet them throughout France.
By Marion Durand.
Cover photo © Marion Durand
Her field of research has taken her 17,000 kilometres from home. Oceanographer Sophie Cravatte settled in New Caledonia more than a year ago, having already spent a long period there from 2011 to 2016.
Since 2004, the physicist has been working at the French National Research Institute for Sustainable Development (IRD), within LEGOS (Laboratory of Space Geophysical and Oceanographic Studies) in Toulouse. So she left the Occitanie region to be closer to the Pacific Ocean, which she has been studying since her thesis in 1999. “I studied maths and physics and was struggling to find a research application that appealed to me in my field. In 1997, I discovered El Niño and La Niña, the natural phenomena that cause cyclones, droughts and rainfall in the Pacific Ocean, during a Masters course. I didn’t know that, as a physicist, you could study the ocean. So I decided to devote my research to it. For her work on these intense climatic phenomena, she won the Christian Le Provost prize in 2012, one of the 40 major prizes awarded by the Académie des Sciences.
On land, at the IRD, or at sea, on expeditions off Nouméa, Sophie Cravatte is now concentrating on the tropical Pacific zone, encompassing New Caledonia and French Polynesia, to study what impacts the ecosystems of the Oceanian lagoons.
Physicist and oceanographer Sophie Cravatte in the port of Nouméa, New Caledonia © IRD – Jean-Michel Boré
She is particularly interested in the variability of the oceans, ‘in what creates exchanges between the surface ocean and the depths’, she explains. In addition to the winds, the sun, the Earth’s rotation and the major climatic phenomena that contribute to ocean circulation, there are other little-known phenomena that contribute to the variation of currents. These include seamounts, the small peaks at the bottom of the oceans. Sophie Cravatte is interested in the unpredictable movements induced by these submerged mountains. ‘When they encounter obstacles such as seamounts, tidal currents generate oscillations within the ocean, known as internal tidal waves,’ explains the oceanographer. This phenomenon leads to the mixing of water masses, which could explain the presence of nutrients and plankton near the surface of the ocean. “This is the first time that tidal waves have been studied off New Caledonia. These phenomena are still very difficult to observe and model’.
“At sea, you’re on holiday from real life”
On 14 March 2023, an initial scientific mission saw the installation of three mooring lines in the seamount region off Ile des Pins, in the Coral Sea Natural Park. These devices record every 20 minutes the variations in currents and density over the entire water column for eight months (from March to November). Sophie Cravatte, head of the Swotalis mission, boarded the Antéa again a few weeks later, one of the oceanographic vessels in the French fleet, to take the first measurements of the mixtures sampled at various depths. “It’s too early to have any results, but we know that what happens on a fine scale has a major impact on ocean circulation and is an essential part of ocean dynamics.
Even though the oceanographer-physicist spends more time on land than at sea, expeditions are ‘magical moments’ for her . “When you’re away, all that counts is the science. We’re on holiday from real life, concentrating 24 hours a day on our research, which is extremely motivating. We feel like modern-day explorers! After twelve expeditions at sea, Sophie Cravatte is still as enthusiastic as ever when the ship leaves the dock. “We’re behind closed doors, and we’re building strong bonds with the researchers and sailors on board. It’s like a holiday camp, and on the last day you’re a bit sad that the campaign is over.
The Swotalis mission has provided a better understanding of ocean dynamics around the seamounts south of New Caledonia © IRD – Jean-Michel Boré
“As oceanographers, we need to sound the alarm”
For several years, the scientist has also been leading research projects on ocean heat waves, abnormally hot periods that affect coastal regions and the ocean. Sophie Cravatte wants to understand these overheating phenomena: What triggers them? Why do they dissipate ? “We are trying to understand these processes because these heatwaves are lasting longer and longer in the Pacific and their consequences are worrying. They influence the migration of species such as tuna, lead to coral bleaching and cause massive mortality in lagoon fish and clams…”
These marine heatwaves are nothing new, although the record temperatures in the Mediterranean and North Atlantic this summer have helped to raise the profile of the problem. “People are asking questions about these heatwaves or phenomena like El Niño. Caledonians here see the coral bleaching and it worries them’, says Sophie Cravatte. On this Pacific island, the ocean plays a central role in the daily lives of the Ultramarines. ‘They wonder how climate change will affect them and how they will have to cope. But at the same time, the oceanographer regrets a lack of ‘awareness’: ‘Caledonians are worried, but they continue to take planes or drive SUVs (large urban vehicles considered to be more polluting, editor’s note). When they ask me about the state of the ocean, I don’t reassure them, I tell them that we have to react, and fast! My role as an oceanographer is to carry out research, but we also have to sound the alarm.
Difficult access to positions of responsibility
While Sophie Cravatte says she has never felt discriminated against because of her gender during her career, she nevertheless believes that women have less access to positions of responsibility. ‘We tend to censor ourselves because we think we are less capable than men’. For the researcher, the marine sciences are a reflection of society as a whole: ‘Women have more doubts about themselves’. This feeling of not being up to the job, the famous imposter syndrome, is holding back some oceanographers, who are ‘just as expert as some men’, when it comes to applying for promotion. ‘But organisations are making an effort, and women are rising to senior positions, so things are going to change,” she predicts.
Sophie Cravatte loads the equipment aboard the Antéa during the Swotalis mission © IRD – Jean-Michel Boré
For Sophie Cravatte, oceanography remains a ‘passionate profession’. She believes that young people, who are increasingly concerned about the environment and climate change, will turn to the marine sciences. “Young people are looking for a useful and meaningful career. Many of them are turning to marine biology’. She does not shy away from the difficulties that surround research: ‘ Oceanography requires a lot of hard work, and it’s true that some PhD students drop out. Recruitment should be opened up earlier so that PhD students don’t have to choose between their professional and personal lives’.
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