Shear Wave Attenuation Field of Heterogeneities in the Earth's Crust and Upper Mantle in the Lop Nor Test Site Area

摘要

Characteristics of the short-period shear (S) wave attenuation field are studied from the records of two digital stations in the Lop Nor nuclear test site region, China (LNTS). The method of study is based on the analysis of the ratio of amplitudes of Lg and Pg, Sn and Pn waves, and Lg coda waves. It is shown that the attenuation is comparatively weak in the Earth's crust in the test region and particularly high in the uppermost mantle. The obtained data are compared with the characteristics of the attenuation field in the regions of two other nuclear test sites: Semipalatinsk (SNTS) and Nevada (NNTS). Peculiarities of the geodynamic processes in these areas are discussed.