Abstract
A new method was developed to reproduce the tsunami height distribution in and around the source area, at a certain time, from a large number of ocean bottom pressure sensors, without information on an earthquake source. A dense cabled observation network called S-NET, which consists of 150 ocean bottom pressure sensors, was installed recently along a wide portion of the seafloor off Kanto, Tohoku, and Hokkaido in Japan. However, in the source area, the ocean bottom pressure sensors cannot observe directly an initial ocean surface displacement. Therefore, we developed the new method. The method was tested and functioned well for a synthetic tsunami from a simple rectangular fault with an ocean bottom pressure sensor network using 10 arc-min, or 20 km, intervals. For a test case that is more realistic, ocean bottom pressure sensors with 15 arc-min intervals along the north–south direction and sensors with 30 arc-min intervals along the east–west direction were used. In the test case, the method also functioned well enough to reproduce the tsunami height field in general. These results indicated that the method could be used for tsunami early warning by estimating the tsunami height field just after a great earthquake without the need for earthquake source information.
Highlights
The 2011 Tohoku-oki earthquake (Mw9.1) generated enormous tsunamis that caused devastation along the Pacific coast of the Tohoku region of Japan (Mori et al 2012)
The Japan Meteorological Agency (JMA) issued tsunami early warning messages and forecasts on tsunami heights along the coast of Japan (Ozaki 2011), approximately 18,000 people were killed by the tsunami
Tsunami numerical simulations are powerful tools to understand the effects of large tsunamis along the coast and the earthquake source processes or to forecast tsunami heights for tsunami warning purposes
Summary
The 2011 Tohoku-oki earthquake (Mw9.1) generated enormous tsunamis that caused devastation along the Pacific coast of the Tohoku region of Japan (Mori et al 2012). Tsunami numerical simulations are powerful tools to understand the effects of large tsunamis along the coast and the earthquake source processes or to forecast tsunami heights for tsunami warning purposes Such simulations have been used extensively in tsunami research communities (Satake 2015; Geist et al 2016). In such tsunami simulations, the initial ocean surface displacement is computed typically from the ocean bottom deformation caused by the faulting of a large earthquake (Tanioka and Seno 2001; Gusman et al 2012), or is assumed the same as the ocean bottom deformation (e.g., Satake et al 2013). The initial ocean surface displacement estimated from the seismic, geodetic, or tsunami waveform data is necessary to compute tsunami propagation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
