Seismic Hazard Assessment in Ningxia Based on GNSS Data

宁夏及周边地区构造活动复杂，是地震多发地区。GNSS资料在地震危险性分析方面能发挥一定的作用，本文基于GNSS资料，获取速度场、应变率场、断层闭锁和跨断层速度剖面等，对宁夏地区地震危险性进行分析，结果表明：三关口断裂南端、罗山断裂北端及南端、烟筒山断裂北端、黄河断裂中北部、贺兰山西麓断裂、六盘山断裂北端存在闭锁，具备中长期发震背景。区域应变率场近年与长期应变率场无显著变化，未来1~3年宁夏及邻区发生大震的可能性较小。The Ningxia region and its surrounding areas are characterized by complex tectonic activity and are prone to frequent earthquakes. GNSS (Global Navigation Satellite System) data can play a significant role in seismic hazard analysis. This study utilizes GNSS observations to derive velocity fields, strain rate fields, fault locking, and cross-fault velocity profiles to assess seismic hazards in the Ningxia region. The results indicate that locked segments exist at the southern end of the Sanguankou Fault, the northern and southern ends of the Luoshan Fault, the northern end of the Yantongshan Fault, the central-northern section of the Yellow River Fault, the western piedmont fault of the Helan Mountains, and the northern end of the Liupanshan Fault, suggesting a medium- to long-term seismic potential. The recent strain rate field shows no significant deviation from the long-term strain rate pattern, implying a relatively low probability of major earthquakes occurring in Ningxia and adjacent areas within the next 1 - 3 years.