Investigation of the Moho discontinuity beneath the Chinese mainland using deep seismic sounding profiles

We herein describe the depth distribution of the Moho beneath the Chinese mainland, determined via compilation and resampling of the interpreted results of crustal P-wave velocity structures obtained from deep seismic soundings (DSSs) performed since the pioneering DSS work carried out in the Qaidam basin in 1958. For the present study, 114 wide-angle seismic profiles acquired over the last 50years were collated; we included results for crustal structures from several profiles in Japan and South Korea, to improve the reliability of the interpolation of the Moho depth distribution. Our final Moho map shows that the depth of the Moho ranges from 10 to 85km. The deepest Moho discontinuity—at approximately 70–85km beneath the Tibetan Plateau—was formed by ongoing continent–continent collision. The Moho beneath the eastern North China craton, at a relatively constant 30–35km, has endured mantle lithosphere destruction. The Moho depths determined from active seismology are consistent (within 3–5km) with results obtained from gravity inversion and surface wave tomography. The spatial variation of the Moho depth, crustal formation, and composition of different tectonic blocks contribute to controls on the spatial distribution of the seismicity and rheology in the crust beneath mainland China. ► We present Moho depth distribution beneath the Chinese mainland from 114 DSS profiles. ► The Moho depths are consistent with the gravity inversion and surface wave tomography. ► Crustal seismicity and rheology of tectonic blocks are closely related to the corresponding structure and composition.