Subsurface Structure in Japan Based on P and S waves Travel Time Analysis Using Genetic Algorithm in Japan Seismological Network
DOI: https://doi.org/10.12777/ijse.6.1.70-74
Abstract
Experiment to obtain the subsurface structure in Japan is conducted using seismograms analysis of earthquakes in Japan. All 101 data was used from events in 2012, selected by a maximum depth of 60 km and magnitude between 4.2 to 5.5 Mj. Determination of 1-D subsurface structure is done by utilizing the inversion method with genetic algorithm approach. P wave and S wave velocity structure are determined based on arrival times at receiver. The crustal thickness is known of 33,66 km. P wave velocity for the upper and lower crust, are 6,03 km/s and 6,92 km/s, respectively, and velocity in the upper mantle is 8,18 km/s. S wave velocity for the upper and lower crust are given 3,38 km/s and 3,89 km/s respectively, and the velocity in the upper mantle is 4,59 km/s. If the range integrated to the stable parameter of velocity structure, it shows stable result and the subsurface structure has sufficiently high compatibility.
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