Optimum Distribution of Seismic Observation Points

Abstract

It is one of the most rundamental problems in seismology to determine the location of the focus, occurrence time and the propagation velocity of an earthquake using the arrival times of waves. It is clear, in this case, that there are good and bad distributions of observation points. For example, if all the points are distributed on a circle and an earthquake occurs on the center of this circle, we can determine neither the occurrence time nor the velocity. On the other hand, if all the points are on a half straight line with the epicenter at the origin of that line, then the velocity can be determined correctly though the focus and the occurrence time can hardly be calculated. Besides, according to the distribution of points, observation errors have large or small effect on the determination of these quantities. The present paper seeks optimum distribution points by means of Monte Carlo method.