Morphostructural, geoseismic and physiographic aspects of endodynamic dangers of the Russian Far East Arctic Region

The article provides a brief substantiation of morphostructural seismological analysis with consideration of the impact of engineering-geological and physiographic conditions on endodynamic events of the Far Eastern Arctic region (such as territorial distribution and specificity of hazardous endodynamic processes and phenomena). The peculiarities of geological, engineering and physiographic conditions in the Far Eastern Arctic region are presented. The features of seismic zone infrastructure, zones and typical areas of the Far Eastern Arctic sector are clarified. The relationship of a number of morphological structures with direct signs of seismic activity (earthquake epicenters and paleoseismodislocations), as well as indirect signs and engineering, geological, physical and geographical conditions of the region (higher gradients of gravity anomalies, different types of permafrost, modern groundwater hydro-thermal sources, as well as various forms of abnormally high endogenous geomorphological processes). As a result, the main sites of potential endodynamic hazard are morphostructural and morphotectonic areas, showing repeated accumulation and compression stress relaxation, tension or shift of mostly high-order morphological structures and associated local morphostructures of central and linear type within long-lived deep Mesozoic-Cenozoic rifts. Among local morphostructures, particular endodynamic hazard is displayed by those with complex features of self-contained sub-horizontal and vertical rotations, "key" morphotectonics and inconsistencies in geomorphological and geodetic data. In assessing of endodynamic hazard, a full range of engineering, geological, physiographic and especially morphostructural criteria and their synergistic effect should be taken into account. Complex analysis of direct and indirect indicators of modern endodynamics of the Far Eastern Arctic region on a morphostructural basis facilitated determination and clarification of new spatial and genetic links of a number of disjunctive morphostructures with certain examples of related activity. There are revealed: 1) inherited activation of skeletal fractures in basic morphostructures from the Mesozoic to Cenozoic age and presently; 2) synergistic impact of predominantly horizontal movements of regional morphostructures and sub-vertical movements of local morphostructures within the typical areas; 3) the highest endodynamic danger is demonstrated by morphostructures with signs of variously oriented rotational movements, many of which are registered for the first time.

Keywords

Authors

References