BONNIEUX , Sébastien

As part of an ERC (European Research Council) project conducted at Geoazur from 2009 to 2015 by Guust Nolet, an autonomous profiler float equipped with a hydrophone and able to carry up to 8 sensors has been developed. It aims to acquire data in oceanic areas, poorly covered by current instrumentation. However, these data are necessary to carry...

We have developed autonomous, Lagrangian floats that make seismo-acoustic measurements in the oceans, with mission durations of 4+ years and running (http://earthscopeoceans.org). Earthquakes generate seismic waves that traverse the solid earth, convert to acoustic waves when they hit the seafloor from below, and are recorded by the hydrophone...

Autonomous floats have been used for decades to monitor physical properties of the oceans. More recently, these instruments have been used to record seismic signals in the oceans in order to improve tomographic images resolution at the global scale. A hydrophone is used to monitor the acoustic landscape but all the data cannot be sent through...

Monitoring of the oceans with autonomous floats is of great interest for many disciplines. Monitoring on a global scale needs a multidisciplinary approach to be affordable. For this purpose, we propose an approach that allows oceanographers from different specialities to develop applications for autonomous floats. However, developing such...

Lagrangian floats are used since the early 2000s for monitoring temperature and salinity of the oceans, and more recently for recording tele-seismic waves. This technology is originally dedicated to global monitoring because it's drifting with oceanic currents over thousands of kilometers. Recent developments have shown that the floats can also...

At 2000 m depth in the oceans, one can hear biological, seismological, meteorological, and anthropogenic activity. Acoustic monitoring of the oceans at a global scale and over long periods of time could bring important information for various sciences. The Argo project monitors the physical properties of the oceans with autonomous floats, some...

Il y a une dizaine d'années, l'un de nous (Gusst Nolet) travaillant avec Frederik Simons à l'Université de Princeton, avait observé une onde sismique P d'un séisme lointain de magnitude 6. Bien qu'il n'est pas rare de voir un séisme de cette ampleur, dont environ 200 se produisent chaque année, leur méthode d'observation était unique : aidé par...

We present methods of data analysis adapted to Mobile Earthquake Recorder in Marine Areas by Independent Divers (MERMAID) seismograms, obtained with hydrophones mounted on moving underwater floats. If the MERMAID float comes immediately to the surface after recording an earthquake signal, the seismogram location is obtained from the first...

Mermaid stands for Mobile Earthquake Recording in Marine Areas by Independent Divers. This autonomous, freely-drifting underwater robot records acoustic conversions of earthquake signals while floating at a water depth of 1.5 km, rising to the surface to transmit such seismograms by satellite. Mermaid is already in use for seismic tomography,...

Our understanding of the internal dynamics of the Earth is largely based on images of seismic velocity variations in the mantle obtained with global tomography. However, our ability to image the mantle is severely hampered by a lack of seismic data collected in marine areas. Here we report observations made under different noise conditions (in...

We present the analysis of more than 9000 hydro-acoustic earthquake records, recorded by a network of 50 instruments called Mobile Earthquake Recording in Marine Areas by Independent Divers (MERMAIDs), which are freely floating in the South Pacific Ocean. This network is part of the collaborative South Pacific Plume Imaging and Modeling (SPPIM)...

We launched an array of nine freely floating submarine seismometers near the Galápagos islands, which remained operational for about two years. P and PKP waves from regional and teleseismic earthquakes were observed for a range of magnitudes. The signal-to-noise ratio is strongly influenced by the weather conditions and this determines the...