Time-dependent fractal characteristics of sets of seismic events

The spatial and temporal interrelations in a set of seismic events were stu died using catalog data on M greater than or equal to 1 earthquakes in the Garm area (the junction zone between the Pamirs and Tien Shan) over the per iod from 1955 through 1991. For this purpose, the correlation integrals (CI s) over both distance and time were calculated for pairs of seismic events. The CIs were calculated separately for earthquakes closely acid widely sep arated in time, if the current parameter was distance, and for events close and remote in space, in the case of integration with respect to time. The calculations showed that mean CI slopes for events that are close in time a nd space are much smaller than for widely spaced events. This result indica tes that events close in space (time) are more ordered in time (space) than widely separated events. The CI curves calculated for events close in time have bends at separations of about 3, 10, and 40 km. This fact may be cons idered as evidence for the presence of characteristic elements with the afo rementioned linear dimensions in the set under consideration. Based on such treatment of the time component of the seismic process, the above pattern of the variation in the IC curve was also revealed in the analysis of two c atalogues of earthquakes in the Caucasus (1962-1990, M greater than or equa l to 2.5) and Fennoscandia (1972-1992, M greater than or equal to 4).