Rapid estimation of tsunami source centroid location using a dense offshore observation network

This paper proposes a rapid method of estimating tsunami source locations using real‐time ocean‐bottom hydrostatic pressure data from a dense offshore observation network. We defined two characteristic locations representing the real‐time tsunami disturbance and the initial sea surface height distribution. First, we defined the tsunami centroid location (TCL), which is the centroid location of the maximum absolute amplitude of the real‐time ocean‐bottom hydrostatic pressure changes. Second, we defined the centroid location of the absolute values of the initial sea surface height displacements. To determine whether the TCL can approximate the centroid location of the tsunami source, we examined approximately 1000 near‐field synthetic tsunami scenarios and a realistic tsunami scenario of the 2011 Tohoku earthquake in the Japan Trench. From these examinations, it was confirmed that in most scenarios, the TCLs obtained within a few minutes after the occurrence of an earthquake were close to the actual corresponding tsunami source locations. Key Points Simple and rapid real‐time method that estimates tsunami source location is proposed Tsunami centroid location (TCL), which is the centroid location of the maximum real‐time absolute amplitudes of waveforms, is defined The tsunami source location could be approximated by the TCL within a few minutes