2024年1月23日新疆乌什发生7.1级地震,震中位于2024年度全国地震重点危险区和新疆地震局划定的年度危险区内,震前做了较好的中、短期预测。本文总结了地震前出现的地震活动和地球物理观测等异常: ①震前地震活动性存在b值、震源一致性、地震平静、条带、增强、高频等异常,长、中、短期异常预测效果均较好; ②地球物理观测震前存在洞体应变、地倾斜、基岩温度、温泉氢气、井流量、地磁等异常,中短期异常较为显著,时、空、强三要素对应较好。综合分析认为,乌什7.1级地震前,地震活动和地球物理定点观测中短期异常突出,对时、空、强均有较好的预测,地球物理观测在震前存在大幅度异常变化,异常具有逐渐向震中逼近的过程。根据异常变化,新疆地震局及时向新疆维吾尔自治区政府上报震情,此次地震取得了减灾实效。

On January 23,2024,a M_S7.1 earthquake struck Wushi,Xinjiang. The epicenter was located within the potential risk area identified in the annual earthquake hazard map published by the China Earthquake Administration and the Xinjiang Uygur Autonomous Earthquake Administration. Medium-term and short-term prediction had been made prior to the event. This paper summarizes the anomalies in seismic activity and geophysical observations leading up to the earthquake. The key findings are as follows: ①Prior to the earthquake,notable anomalies were observed,including seismic quietness,banding,enhancement,high-frequency events,b-value changes,and source consistency. These indicators provided effective predictions for long-,medium-,and short-term forecasting. ②Abnormal geophysical phenomena,such as ground tilt,gravitational changes,elevated fault gas radon levels,bedrock temperature variations,and geomagnetic shifts,were detected before the earthquake. These anomalies were particularly pronounced in the short-to medium-term and showed strong correlations in terms of spatial,temporal,and intensity parameters. ③ No significant anomalies were observed macroscopically prior to the earthquake,but two cases of unusual animal behavior were recorded afterward. A comprehensive analysis reveals that the Wushi M_S 7.1 earthquake was preceded by distinct short-term anomalies in both seismic activity and geophysical monitoring. These anomalies enabled accurate predictions in terms of timing,location,and magnitude. The geophysical indicators showed significant abnormal changes before the event,with regional anomalies progressively converging toward the epicenter in the short term. Based on these observations,the Xinjiang Earthquake Administration promptly informed the Xinjiang Uygur Autonomous Region government,facilitating effective disaster mitigation measures.

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新疆维吾尔自治区重点研发项目(2020B03006-3)、新疆维吾尔自治区自然科学基金(2023D01A104)共同资助