SEGJ Technical Conference

Phase velocity estimated from rotational components of the simulated microtremor array records and its resolvable range

Abstract Phase velocities of rotational components of the simulated microtremor array records by using 3-D finite difference in one layered stepwise structure were estimated. The rotational component was calculated from spatial derivatives based on the first-order Taylor series expansion. Phase velocities at two sites were estimated from the square array (sq5p) of the rotational component by using eSPAC method. The estimated phase velocities of the rotational components agree well with the Love wave phase velocities theoretically calculated from the velocity structure models beneath the sites. We calculated coherences of the rotational components estimated from various array distances at the center of the array. The result suggests that the shortest resolvable wavelength to calculate rotational component is approximately 3 times of the array distance.