Randomly distributed unit sources to enhance optimization in tsunami waveform inversion

Abstract. In tsunami waveform inversion using the conventional Green's function technique, an optimal solution is sometimes difficult to obtain because of various factors. This study proposes a new method to both optimize the determination of the unknown parameters and introduce a global optimization method for tsunami waveform inversion. We utilize a genetic algorithm that further enhanced by a pattern search method to find an optimal distribution of unit source locations prior to the inversion. Unlike the conventional method that characterized by equidistant unit sources, our method generates a random spatial distribution of unit sources inside the inverse region. This leads to a better approximation of the initial profile of a tsunami. The method has been tested using an artificial tsunami source with real bathymetry data. Comparison results demonstrate that the proposed method has considerably outperformed the conventional one in terms of model accuracy.

[1]  Fumihiko Imamura,et al.  Far-Field Tsunami Potential and a Real-Time Forecast System for the Pacific Using the Inversion Method , 2003 .

[2]  Chen Ji,et al.  Rupture Process of the 2004 Sumatra-Andaman Earthquake , 2005, Science.

[3]  Ian Parsons,et al.  Surface deformation due to shear and tensile faults in a half-space , 1986 .

[4]  Jürgen Branke,et al.  Evolutionary optimization in uncertain environments-a survey , 2005, IEEE Transactions on Evolutionary Computation.

[5]  P. Liu,et al.  TSUNAMI SOURCE REGION PARAMETER IDENTIFICATION AND TSUNAMI FORECASTING , 2008 .

[6]  A. Gusman,et al.  Effect of the largest foreshock (Mw 7.3) on triggering the 2011 Tohoku earthquake (Mw 9.0) , 2013 .

[7]  D. E. Smylie,et al.  The displacement fields of inclined faults , 1971, Bulletin of the Seismological Society of America.

[8]  C. Amante,et al.  ETOPO1 arc-minute global relief model : procedures, data sources and analysis , 2009 .

[9]  O. SIAMJ.,et al.  ON THE CONVERGENCE OF PATTERN SEARCH ALGORITHMS , 1997 .

[10]  Margaret J. Eppstein,et al.  A hybrid genetic algorithm with pattern search for finding heavy atoms in protein crystals , 2005, GECCO '05.

[11]  Shunichi Koshimura,et al.  Tsunami source of the 2004 off the Kii Peninsula earthquakes inferred from offshore tsunami and coastal tide gauges , 2005 .

[12]  H. Latief,et al.  Slip distribution of the 2007 Bengkulu earthquake inferred from tsunami waveforms and InSAR data , 2010 .

[13]  I. Mulia,et al.  DETERMINATION OF THE INITIAL SEA SURFACE DEFORMATION CAUSED BY A TSUNAMI USING GENETIC ALGORITHM , 2014 .

[14]  T. Baba,et al.  Compound fault rupture during the 2004 off the Kii Peninsula earthquake (M 7.4) inferred from highly resolved coseismic sea-surface deformation , 2005 .

[15]  Stefano Lorito,et al.  Rupture Process of the 2004 Sumatra-Andaman Earthquake from Tsunami Waveform Inversion , 2007 .

[16]  T. Furumura,et al.  Tsunami waveform inversion including dispersive waves: the 2004 earthquake off Kii Peninsula, Japan , 2010 .

[17]  Goldberg,et al.  Genetic algorithms , 1993, Robust Control Systems with Genetic Algorithms.

[18]  David E. Goldberg,et al.  Genetic Algorithms in Search Optimization and Machine Learning , 1988 .

[19]  Eric L. Geist,et al.  Complex earthquake rupture and local tsunamis , 2002 .

[20]  Edite Manuela da G. P. Fernandes,et al.  Hybrid genetic pattern search augmented Lagrangian algorithm : application to WWTP optimization , 2010 .

[21]  Hajime Mase,et al.  Real-Time Tsunami Prediction by Inversion Method Using Offshore Observed GPS Buoy Data: Nankaido , 2013 .

[22]  Robert Hooke,et al.  `` Direct Search'' Solution of Numerical and Statistical Problems , 1961, JACM.

[23]  Kazuhiro Kimura,et al.  Near-field tsunami forecasting using offshore tsunami data from the 2011 off the Pacific coast of Tohoku Earthquake , 2011 .

[24]  Reconstruction of initial Tsunami waveforms by a truncated SVD method , 2011 .

[25]  Kenji Satake,et al.  Inversion of tsunami waveforms for the estimation of a fault heterogeneity: Method and numerical experiments. , 1987 .

[26]  Tso-Ren Wu,et al.  High resolution tsunami inversion for 2010 Chile earthquake , 2011 .

[27]  Eric L. Geist,et al.  Local tsunami hazards in the pacific northwest from cascadia subduction zone earthquakes , 2005 .

[28]  Jonathan A. Wright,et al.  COMPARISON OF A GENERALIZED PATTERN SEARCH AND A GENETIC ALGORITHM OPTIMIZATION METHOD , 2003 .

[29]  I. Aida.  Numerical Estimation of a Tsunami Source , 1972 .

[30]  Slip distribution of the 2003 Tokachi‐oki Mw 8.1 earthquake from joint inversion of tsunami waveforms and geodetic data , 2010 .

[31]  A. Barnston.  Correspondence among the correlation, RMSE, and Heidke forecast verification measures; refinement of the Heidke score , 1992 .