Current Tectonic Stress and Activities Characteristics of the Deep Faults Within Weihe Basin

Using high precision GPS data for the period of 2001-2010 of Weihe basin, adopting the finite element numerical analysis method, we obtained the current tectonic stress fields and activities characteristics of deep faults in the Weihe basin. These results show that: the deep faults in western basin present significant compressive stress characteristics in the nearly E-W direction. In central area, obvious tensile stress appears in the NW-SE direction, in east deep faults also present certain tensile stress in the NW-SE direction, but the magnitude is smaller than the central area. Even for the same deep fault with different trends, in different sections, the stress characteristics, values, and activity rates are divergent. The velocity components along the strike of the deep faults show certain changes at both ends of the faults, revealing deep faults in the Weihe basin with twist characteristics. The results further reveal that compared to western and eastern basin, the central area is significantly influenced by the tensional stress in the NW-SE direction. These areas are where deep faults intersect, with tensile stress in central basin, especially in sections with higher movement rates; they show the most developed ground fissure hazards.