世界における地震観測精度の分布

抄録

The accuracy of the determination of earthquake parameters is strongly governed by the geographical distribution of seismic stations and the epicenter. In order to estimate this effect quantitatively, the distributions of the expected error of the epicenter location and the origin time of earthquakes are calculated by the Monte Carlo method. As the observation points 124 standard stations are assumed which belong to WWSSN, though only the ones with epicentral distance <105° are actually adopted. As the observation errors at each station normally distributed random numbers are used with the mean value 0 and the standard deviation 1.0sec. Similar calculations are repeated 400 times for each assumed epicenter which is distributed on the earth's surface with the interval of 10° both in latitude and longitude (except the area near the poles). The result is shown in the form of figures.