Contact R&D: A. Sladen
In order to address the critical lack of data on the dynamics and physical evolution of the seafloor (coastal erosion, tectonic or volcanic motions, gravitational instabilities, etc.), we are exploring the potential of Distributed Fiber-Optic Sensing (DFOS) technology to complement or improve existing seafloor monitoring techniques.
Contact R&D: Y. Hello
MUG is a multichannel 3 and half year’s autonomy ocean bottom system named MUG-OBS (Multi-parameters Geophysical Ocean Bottom System) allowing the acquisition of various seismic and environmental parameters. Initially developed for a 3-channel seismometer (Trillium compact 120s), a 3-channel accelerometer, a Differential Pressure Gauge (DPG), an absolute pressure sensor including a hydrophone, the acquisition system can interface other sensors.
A DOMINO optical telecom link (Demonstrator for Optical teleMetry at hIgh data rate iN earth Orbit) between the Japanese satellite SOCRATES and the MeO ground station (figure) was first created at the Côte d'Azur Observatory on the Calern site in June 2015.
Contact R&D: Y. Hello
Since 2009, with funding by the ERC (European Research Council), G. Nolet (now professor emeritus at the Université Côte d'Azur), and the R&D division of Géoazur under the direction of Yann Hello, have developed a robot which drifts at programmed depths in the oceans and communicates at regular intervals by Iridium satellite with our researchers. This "MERMAID" is able to record seismic waves at sea in order to image the interior of our planet Earth (Hello et al., 2011, 2020; Sukhovich et al., 2011, 2015).
In 2019, one of the FIEEC CARNOT Applied Research Prizes, which rewards researchers who have carried out a research partnership with industry that had a real economic impact, was awarded to Yann Hello from Geoazur.
In 2020, no less than 51 third generation Mermaids had already been launched in the South Pacific (see: geoweb.princeton.edu/people/simons/earthscopeoceans), and more than 30 are being prepared for other projects. Previously, a deployment of MERMAIDS near the Galapagos Islands made it possible to obtain the image of a deep mantle plume under this archipelago (Nolet et al., 2019).
Geoazur's R&D division, in collaboration with engineers from OSEAN SARL in Pradet, is currently developing not only a "Lander" version for rapid deployment after large earthquakes, but also the next generation of this float, which will be remotely programmable and which can host up to eight different sensors. The current version is already capable of observing the temperature and salinity of the ocean in addition to seismic waves.
Hello, Y., and 3 others, Modern Mermaids: new floats image the deep Earth, EOS Trans. Am. Geophys. Union, 92, 337-338, 2011, doi:10.1029/2011EO400001
Hello, Y. and Nolet, G., Floating Seismographs (MERMAIDS), in: H.K. Gupta (ed.), Encyclopedia of Solid Earth Geophysics, Springer Int. Publ., 6p., 2020, doi: 10.1007/978-3-030-10475-7_248-1
Nolet,G., and 10 others, Imaging the Galapagos mantle plume with an unconventional application of floating seismometers, Sci. Rep., 9, 1326, 2019 (https://www.nature.com/articles/s41598-018-36835-w)
Sukhovich, A., and 6 others, Automatic discrimination of underwater acoustic signals generated by teleseismic P-waves: a probabilistic approach. Geophys. Res. Lett., 38, L18605, doi:10.1029/2011GL048474, 2011.
Sukhovich, A., and 5 others, Seismic monitoring in the oceans by autonomous floats, Nature Comm., 6, 6p., 2015, doi:10.1038/ncomms9027.
Contact R&D: E. Samain
From 2008 to 2014, the T2L2 instrument executed some 600 million timestamps, showing that it is possible to remotely compare clocks with a degree of uncertainty better than 500 picoseconds. The clock frequency of the DORIS oscillator on Jason-2 has also been validated with unprecedented precision. But above all, T2L2 has paved the way for new experiments, notably for the future European Laser Timing link (ELT) that will be part of the Atomic Clock Ensemble in Space (ACES) scheduled to be launched to the International Space Station in 2016. The T2L2 experiment is currently conducting other optical telecommunications tests.