Construction of the high-velocity model of the earth's upper crust of the Eurasian and Okhotsk sea plates conjunction zone along the North-Eastern segment of the 3-DV profile based on the results of digital processing of compressional and shear-wave refractions
An automated algorithm for monitoring the areas of refraction event tracing along the profile based on the dynamic conversion was developed. Time sections of compressional- and shear-wave refractions recorded by the CDP shooting geometry in the Northeastern segment of the 3-DV survey base line were constructed. A high-velocity model of the upper part of the Earth's crust was constructed to a depth of 2 km in the Sea of Okhotsk-Eurasian plate conjunction zone. Based on the increased velocity ratio of P- and S-waves, the refracting boundaries in the Ayan-Yuryakh block were rock sections with various lithological compositions in the sedimentary cover. The zone of reduced P-wave velocity and Vp/Vs ratio related to high rock fragmentation was identified in the high-velocity profile of the Chai-Yurya Fault zone, both above and below the refracting boundary. The velocity values of P- and S-waves (6.0-6.1 and 3.6-3.7 km/s, respectively,) and reduced Vp/Vs ratio (˜1.65) due to felsic rock intrusions were recorded in the southern part of the Inyali-Debin block within the depth range of 1-1.5 km.
