Asymmetrical co-seismic surface ruptures and aftershock sequences of East Kunlun, Wenchuan, and Yushu strong earthquakes in the northeastern Tibetan Plateau propagated eastward, southeastward and northeastward, respectively. These earthquakes may generally be related to the variation in flow velocity and flow direction of the arc lower crustal “thermal river” that originates from Ganges Basin and flows through Yadong, Damxung, Amdo, Kusai Lake, Zhidoi, Ganzi, Wenchuan toward Yunnan Province and its adjacent areas forming a lower crustal “thermal sea”, which caused a 10-month mega tectonic drought. The co-seismic surface ruptures did not precisely coincide with faults, and hypocenters did not precisely occur on brittle faults. Lower crustal flow controlled seismic sources in middle crust and then caused brittle fracture system in upper crust. Strong earthquake swarms often occurred on the basin-orogen boundary. Continental intraplate earthquakes were product of stratification deformation of active crust driven by lower crustal laminar flow.
