2022年6月1日,四川省芦山县发生6.1级地震,四川地震预警台网成功处理并产出了本次地震预警结果。本文针对四川地震预警台网部署的JEEW和EEW两套地震预警系统的预警处理能力及减灾效能进行分析。融合决策系统将多套地震预警系统产出的预警处理结果进行融合选优后,在震后6s对外发布了第1次地震警报。与正式地震目录对比,第1次地震警报的震中位置偏差2.4km,震级偏差1.4级。第1次地震警报的盲区半径为12.3km,并且向盲区以外,地震烈度为Ⅶ、Ⅵ度的预警有效获益区提供了0～6s的预警时间,减灾效能显著。利用此次地震,从观测数据质量、地震预警参数和预警效能等方面进行深入分析,有助于对四川地震预警台网部署的地震预警系统进行优化升级,进一步提升地震预警能力和发挥减灾效能。

On June 1,2022,an M6.1 earthquake struck Lushan County in Sichuan Province. The Sichuan Earthquake Early Warning Network adeptly processed and disseminated early warning information for this seismic event. This paper evaluates the early warning processing capabilities and disaster mitigation efficiency of two systems within the network:the Joint Earthquake Early Warning(JEEW) and Earthquake Early Warning(EEW) systems. Utilizing a fusion decision system,the early warning outputs from multiple seismic warning subsystems were synthesized and refined. The initial earthquake warning was issued a mere 6 seconds post-seismic event. When juxtaposed with the official earthquake catalog,the initial warning exhibited a 2.4km deviation in epicenter location and a 1.4 unit deviation in magnitude. The earthquake warning blind area has a radius of 12.3km. For regions with an effective early warning benefit and experiencing earthquake intensities of Ⅶ and Ⅵ,outside this blind area,a warning time of 0 to 6 seconds was provided,demonstrating significant disaster reduction efficiency. Drawing from this case study,the paper further scrutinizes the quality of observational data,parameters influencing earthquake early warning,and the overall efficiency of the early warning system. Such an analysis holds substantial value,offering critical insights for the assessment of early warning processing capabilities and their contribution to disaster mitigation.

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四川省地震局地震科技专项(LY2302)、四川省地震局地震科技项目(SCSDZJKJFW2023042)共同资助