Negative Dislocation Model Parameters Inverted from GPS Data in North China

In this paper,the data obtained by three GPS campaigns in 1995,1996,and 1999 in North China have been used to study the intraplate tectonic block movement model in this area.By Bayesian inversion method,negative dislocation distribution on three main fault zones and individual relative movement between four intraplate tectonic blocks has been obtained based on the GPS data.Accordingly,the intensity of fault lock has been distinguished and the fault with biggest possibility of potential earthquake has been pointed out.The obtained negative dislocation values on the Front Taihang Mountain Fault are(-5±2) mm/a in tensile component and(2±2) mm/a in both strike and dip component,which indicate that this fault suffers the pull apart tectonic movement.On the Tangshan-Ninghe Fault,the obtained negative dislocation values are(-3±3) mm/a in dip,(-2±2) mm/a in tensile and(-1±3) mm/a in strike,which indicates that the east part of this fault still have upward movement.On the Zhangjiako-Beipiao Fault,the obtained negative dislocation values are(-4±2) mm/a in strike,(0±2) mm/a in dip,and(1±2) mm/a in tensile,which indicate that this fault has sinistral strike movement.According to the inversion results,the southern part of the Zhangjiako-Beipiao Fault suffers the pull tectonic movements caused by the recent upward movement at the east part.The pull tectonic movements are almost totally blocked on the Front Taihang Mountain Fault.So the Front Taihang Mountain Fault is a potential earthquake source,more crustal deformation monitoring work should be applied in this area.