S-Net project: Performance of a Large-Scale Seafloor Observation Network for Preventing and Reducing Seismic and Tsunami Disasters

S-net is the online and real-time seafloor observation network of 150 observatories for earthquakes and tsunamis along the Japan Trench. It covers the focal region of the 2011 off the Pacific coast of Tohoku earthquake and its vicinity regions. It was established to enhance reliability of early warnings of tsunami and earthquake after the occurrence of the earthquake. Full-scale operation of the S-net has started since April 2017. The data from the 150 seafloor observatories are being transferred to the data center at NIED on a real-time basis, and then verification of data integrity are being carried out. Obtained data reveal that the S-net can observe and monitor seismic and tsunami phenomena that had been never covered only by land-based observations.