THE PAIRED EARTHQUAKES WITHIN THE KAMCHATKA PENINSULA SUBDUCTION ZONE

During 1962 to 1993 three earthquakes were recorded of seismic moments greater than 10(19) Nm (M-w = 6.9 to 7.0) at depths from 0 km to 99 k m within the Kurile-Kamchatka subduction zone near Kamchatka Peninsula . These earthquakes have been occurred along the coast of the Peninsul a under the dominating compressive stresses and thrust-faulting. These three earthquakes occurred in pairs; they were preceded by moderate-s ize (seismic moments from 10(18) Nm to 10(19) Nm) earthquakes located at distances from 10 km to 41 km from the epicentre of the large earth quake one to four years before the large event. Each time the moderate -size event was the first one, accompanied by aftershocks after a long -term sequence of single events in this area. This regularity in appea rance of paired earthquakes can be used as an additional criterion to intermediate-term precursors to large earthquakes in the Kamchatka sub duction zone. (C) 1998 Elsevier Science B.V. All rights reserved.