Geophysical processes and biosphere: article

Аnnotation: Based on a review of published space geodesy data in South-East Asia, the assumption is con-firmed that the central part of the region – the Sunda plate – can be considered as a rigid stable block with a continental lithosphere. Based on the totality of geodetic, geological and seismologi-cal data, the position of the boundaries of this block (Sundaland) is specified. For the most part, these boundaries are represented by subduction zones, as well as areas of modern continental tec-tonic deformation of the Earth's crust. Moreover, the overwhelming proportion of deformation is concentrated precisely within the boundaries of Sundaland. Based on data about focal mechanisms of earthquakes, the type of seismotectonic deformation tensor (STD) was estimated within 21 spa-tial samples in the vicinity of various sections of the Sundaland border. The results of these esti-mates, compared with the known geological and geodetic data, showed a satisfactory agreement between them. The type of STD was estimated for the entire depth of subduction zones accessible to observations, and an interpretation was given of the revealed variations of the type of STD with depth.