Analysis of Stress Variation Characteristics of Jiangling Depression, Hubei, China, Based on Jingzhou Well Water Level and GNSS Data

Abstract

There have been many M ≥ 3.0 earthquakes in and around the Jiangling Depression in history, and the stress variation can directly affect the preparation of surrounding earthquakes. This paper innovatively uses the variation characteristics of Jingzhou well water level and GNSS data to analyze the stress variation in the Jiangling Depression. The results show that (1) the long-term decline trend of Jingzhou well water level has little correlation with rainfall and is mainly from deep source, which is different from the recharge source of the surrounding water system. The long-term decline trend of Jingzhou well water level is mainly affected by the tension state of the region. (2) The strain rate in the northern part of the study area is relatively high, and the tension state in the NNW direction is dominant. The slope of HBJM-HBJL stations baseline time series is positive, indicating that the NNW-SSE is in a tension state as a whole, which is consistent with the trend of Jingzhou well water level. (3) Jingzhou well water level and GNSS baseline time series have good synchronization, which directly reflects that the stress field in and around Jiangling Depression is in a state of tension in recent years. There have been many ≥ 3.0 earthquakes in and around the Jiangling depression in history. In the future, it is worth noting when the stress–strain state of the study area changes.