Seismic monitoring in the oceans by autonomous floats
|Author(s)||Sukhovich Alexey1, Bonnieux Sebastien2, Hello Yann2, Irisson Jean-Olivier3, Simons Frederik J.4, Nolet Guust2|
|Affiliation(s)||1 : Univ Bretagne Occidentale, UMR Domaines Oceaniques 6538, Univ Europeenne Bretagne, CNRS,IUEM, F-29280 Plouzane, France.
2 : Univ Nice, Geoazur, UMR 7329, F-06560 Valbonne, France.
3 : UPMC Univ Paris 06, Univ Sorbonne, CNRS, LOV, F-06230 Villefranche Sur Mer, France.
4 : Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA.
|Source||Nature Communications (2041-1723) (Nature Publishing Group), 2015-08 , Vol. 6 , P. 8027 (6p.)|
|WOS© Times Cited||24|
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 the Mediterranean Sea, the Indian and Pacific Oceans) by a submarine floating seismograph, and show that such floats are able to fill the oceanic data gap. Depending on the ambient noise level, the floats can record between 35 and 63% of distant earthquakes with a moment magnitude M >= 6.5. Even magnitudes <6.0 can be successfully observed under favourable noise conditions. The serendipitous recording of an earthquake swarm near the Indian Ocean triple junction enabled us to establish a threshold magnitude between 2.7 and 3.4 for local earthquakes in the noisiest of the three environments.