[J04-5] Geohazard early warning systems V

[J04-5-03] Evaluating the efficiency of a tsunami warning system to recover a tsunami source based on the r-solution method

Tatyana Voronina^{1, 2}, Alex Romanenko², Artem Loskutov³, ^○Vladimir Cheverda⁴ (1.Institute of Computational Mathematics and Mathematical Geophysics of SB RAS, 2.State University Novosibirsk Russia, 3.Institute of Marine Geology and Geophysics, FEB RAS Yuzhno-Sakhalinsk, Russia, 4. Institute of Petroleum Geology and Geophysics)

The mega thrust earthquakes quite often result in large tsunamis that may inflict a severe loss and pain to the population of the coastal communities. The development of the Tsunami Warning Systems is likely be the most constructive way in the mitigation of the destructive effect of potential tsunamis. To accurately forecast the inundation and run up in the near-field coast, where a warning should be issued in no more than 20 minutes, it is necessary to gain the insight into a tsunami source at the early stages of tsunami propagation. We offer a method for recovering a tsunami source and taking into account a particular arrangement of the monitoring system with respect to a tsunami source area and the sea bottom topography, we have developed the inversion method where the inverse problem operator was regularized by the least square inversion using the truncated Singular Value Decomposition approach. This method is based on the inversion of remote measurements of the water-level data without a priori information on a source but on their general spatial localization. Analyzing the singular spectra of a matrix obtained by numerical calculations one can estimate the subsequent inversion by a certain observational system that will allow offering a more effective disposition for the tsunami wave recorders by precomputations. The results obtained allow revealing the way to improve the inversion by selecting the most informative set of available recording stations. To avoid potential instability of the numerical solution, the r-solution method is used. This method seems to be attractive in view of computations since the main efforts are required for calculating the matrix to be obtained. In this study, we apply the approach proposed to evaluating the efficiency of a tsunami warning system to recover areal tsunami sources for the event of 6 February, 2013 near the Solomon Islands and for the event of 16, September, 2015 (Illapel, Chile).