BOYKO RNGUELOV - Assoc. Professor, Geophysical Institute, BAS, Sofia, Bulgaria
ELISSAVETA RAKOVA - Plovdiv University, Plovdiv, Bulgaria

A pair analysis has been applied for several good documented aftershock sequences, including well known earthquakes nea: Coalinga, USA, May ۱۹۸۳; Pap, Azerbaijan, February ۱۹۸۴ and Spitak, Armenia, December ۱۹۸۸. The time and space statistical distributions have been approximated with the best fitting functions for each pair of the consecutive aftershocks. The main aim of this approach is to create formal criteria for recognition of the difierent sources and suong earthqu.ikes in different tectonic active areas. The results obtained show that this approach is relatively effective for these purposes.