Creepex-study of the seismic-geodynamic situation on the eve of strong earthquakes in the continental part of southeastern Eurasia

According to the catalogues of the Altai-Sayan, Baikal and Yakut branches of the GS RAS from the collections “Earthquakes of Northern Eurasia” using the algorithm for finding KCOR anomalies (the coefficient of paired correlation of the normalized creepex Cr0cat and magnitude MS), preceding strong earthquakes of energy class K≥14.8 (MS≥6.2), the dynamics of the seismic-geodynamic process on the eve of these events is investigated. Starting in 1989, 33% of earthquakes of K≥14.8 in the Altai-Sayan folded region, the Baikal rift zone, and the Yakut region have the long-term (from 20 days to 10 months) negative anomalies of KCOR≤–0.7 in the l-area of remote influence on their foci preparation. All these events are confined to the northern border of the South Asian structure, which belongs to the inland part of southeastern Eurasia (anomalies on the eve of other events are either positive or statistically unrepresentative). For example, for the largest earthquakes in the Yakutsk and Altai regions (Altai earthquake of September 9, 2003, K=17 and Charudinsk-II of December 11, 2005, K=15.9) the detected anomalies begin 32 days before these events. They are identical to negative anomalies in terms of the seismicity of the entire region preceding these events, which probably indicates the consolidation of the environment on the eve of events in an area far exceeding the radius of l. However, when using the KCOR0 parameter (the pair correlation coefficient of the classical creepex Cr0 and magnitudes MS), the scanning algorithm for catalogs of these regions revealed significantly longer positive seismic anomalies in the l-vicinity of strong earthquakes (from one and a half to nine years). They are present before all K≥14.8 earthquakes without exception and may indicate longer processes of plastic restructuring of the environment in the area of remote influence on the preparation of a major earthquake.