[J04-P] Poster

[J04-P-05] Development of semi-real-time tsunami calculation system for ocean-bottom pressure gauge stations in southwestern and northeastern Japan

^○Takeshi Nakamura, Narumi Takahashi, Wataru Suzuki, Naotaka Yamamoto (National Research Institute for Earth Science and Disaster Resilience, Tsukuba, Japan)

Ocean-bottom pressure gauge data are useful for detecting tsunami signals at suboceanic earthquakes and rapidly issuing warnings to coastal areas. We developed a semi-real-time calculation system that measures pressure perturbations at pressure gauge networks installed in offshore areas of southwestern and northeastern Japan (called DONET and S-net, respectively) in order to identify tsunami signals. The system automatically calculates geodetic deformations and tsunami propagation immediately after getting seismic source information on hypocenter, magnitude, and mechanism. The calculation area and grid size are categorized into four different areas and sizes, respectively, from the epicentral location of an earthquake to conduct an efficient calculation from the source to the networks. The calculation results for transoceanic tsunamis in a 7.5 arc-minute grid can be available in approximately 35 s after getting source information to output waveform data by executing the optimized parallel calculation code on our computer server. System operations began in July 2015 and have been applied to tsunamigenic earthquakes in the Pacific Ocean. The system is effective in identifying tsunami signals and automatically predicting tsunami propagation in offshore areas, which may be useful for further data analyses on tsunami propagation.