The Earth’s Crust of the Western Orenburg Region According to the Receiver Function Data

The properties of the Earth’scrust of the western Orenburg region are discussed. The data analysis of the broadband seismic station ORR (Orenburg), which is part of the “Neftegaz-Seismika” network, was carried out using the receiver function method. The Zhu-Kanamori method was used to estimate the average parameters of the crust — the thickness and the ratio of the longitudinal and transverse velocities of seismic waves — within the framework of a single-layer model. A one-dimensional section of seismic wave velocities under the station was obtained by inversion of the waveforms of the receiver function. It is shown that the upper part of the constructed section is characterized by low values of transverse wave velocities. This is consistent with the presence of terrigenous and oil- and gas-containing rocks under the seismic station. The obtained section, in general, does not contradict the interpretation results of two DSS profiles performed in this region, except that the crustal thickness calculated by the receiver function method and approximately equal to 35–37 kmturns out to be 7–10 kmless compared to the DSS results. In order to make a final conclusion about the crustal thickness in the region, additional research on observations of a larger number of broadband seismic stations is required.

the western Orenburg region, Neftegaz-seismika, receiver function, Zhu-Kanamori method, crustal thickness, seismic velocity ratio