Crust uplift controls the massive emissions of 222Rn and CO2 in the Northeastern Tibetan Plateau, China

The northeastern Tibetan Plateau (NETP) is the most intensely uplifted deformation region in the Tibetan Plateau. The intense gas release caused by uplift has attracted widespread attention. In this study, we measured the soil gas concentrations (Rn and CO2) and CO2 fluxes from active faults and analysed the seismic tomography in the arcuate structure zone of the NETP. The results reveal that the concentrations and fluxes of Rn and CO2 in the south area are higher than those in the north area. Factors such as rock types, meteorological conditions, and seismicity have limited influence on soil gas emissions. Instead, the uplift of the upper crust in the Tibetan Plateau plays a crucial role in determining the distribution of soil gases. Regions with high crack density (epsilon), saturation rate (xi) and Poisson's ratio (sigma) in the upper crust show stronger release, such as the epicenter of the Haiyuan M-S 8.5 earthquake. The convergence zone of the arcuate structure zone with high crust uplift velocity is an intense release area with a rough total CO2 output of similar to 1.10 Mt.<middle dot>yr(-1). This output is twice the annual CO2 output of the Wenchuan M-S 8.0 earthquake rupture and one-fifth of the annual CO2 output of Amiata volcano, Italy.