On our way to the Southeast Indian Ridge and it’s all hands on deck 🚢🔧
From building tripods for acoustic beacons to installing the transducer and modem in the ship’s forward hold, operational prep is well underway!
The OHA-GEODAMS Seafloor Observatory
The A-0-A lets us measure vertical displacements of the seafloor: if the ground swells, the instrument will go up, feel less water weight, and the pressure will decrease.
The OHA-GEODAMS team is back to document how the Indian Ocean grows.
Cruise #3 on board Marion Dufresne left La Réunion Island a few days ago to maintain the multi-sensor observatory on the South East Indian Ridge. Follow us on this new adventure!
(credit photo: Ewen & Didier)
Last, but not least, we also recovered and re-deployed an A-0-A pressure sensor, right in the middle of the ridge's axial valley. This state-of-the-art instrument corrects its own drift by regularly re-calibrating itself against an inner chamber where the pressure is known.
If it all goes well, our now-complete observatory will be the first to document seafloor spreading and transform faulting events with geodesy, hydro-acoustics, and seismology! 🤞
What a day!
We visited Kerguelen station, met king penguins and elephant seals, and walked on the "Desolation Island".
Just a few days before reaching the OHA-GEODAMS area, this was an unforgettable stop in the middle of the Southern Ocean.
Cheers to the penguins 🐧
The 2026 GEODAMS team safely arrived close to Possession Island in the Crozet archipelago a few days ago. A penguin crowd welcomed us under a very bright sky and with the traditional croziflette that follows... 🐧 🍽️
We’ve had our fill, both for the eyes and the stomach.
But pressure at the seafloor can fluctuate for many reasons! Tides, ocean dynamics, etc... To avoid misinterpreting an oceanographic signal as a tectonic signal, we deployed a mooring that will help us assess how the weight of the water column changes through time.
