Abstract:
Using GNSS observation data in Hebei and surrounding areas, the velocity field of horizontal motion in Hebei region from 2010 to 2021 was obtained. According to the distribution of GNSS stations and seismic risk, Hebei region was divided into different regions, and the temporal and spatial variation characteristics of strain results in Hebei region were summarized and compared with other precursor observation methods. The results show that: in the horizontal movement direction, the movement direction of the 8 stations in the province is in the southeast direction in the global frame of reference; after deducting the overall movement within the region, the relative horizontal movement of the measuring stations in the province is not significant, and the magnitude of the 6 measuring stations is within 1 mm/yr, reflecting that the overall horizontal movement of the region is relatively stable, with little annual change. From the perspective of strain zoning, the principal compressive stress in the border area of Shanxi、Henan and Hebei province decreased in 2018. The principal compressive stress in the border area between Hebei and Shandong has increased since 2016. The principal compressive stress in the beijing-Tianjin-Hebei border area decreased in 2016. The principal tension stress in Tangshan and Tianjin decreased in 2016. In the western part of the Zhangjiakou-Bohai fault and the Zhangjiakou area, the decrease of the principal pressure strain slowed down in 2016, and the principal tension stress increased in 2018. Since the second half of 2017, the principal compressive stress in the border area between Shanxi, Hebei and Inner Mongolia has decreased. The above GNSS processing results show that the overall movement in Hebei is relatively stable, and there is a certain relative movement and time adjustment in the internal region.