Analysis of the Earthquake Early Warning of the Luding M6.8 Earthquake on September 5, 2022
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摘要: 2022年9月5日,四川省泸定县发生M6.8地震。针对四川地震预警台网部署的EEW和JEEW地震预警处理软件产出的地震预警信息进行分析,从观测数据质量、预警参数测定、减灾效能等方面对地震预警处理过程进行系统性分析,检验预警软件处理结果的可靠性。结果表明,EEW和JEEW分别在震后 4.4、8.2 s产出了首报预警信息,震级偏差分别为−1.6、−0.8,震中位置偏差分别为11.2、0.8 km,随着时间的延长和触发台站的增多,预警处理结果最终与正式目录结果趋于一致;本次地震预警盲区半径为14.7 km,预警盲区以外,烈度Ⅵ度以上区域的预警时间为0~21 s,预警有效获益区内减灾效能显著。Abstract: On September 5, 2022, a M6.8 earthquake struck Luding county, Sichuan province. This paper examines earthquake early warning information generated by two sets of earthquake early warning processing software, EEW and JEEW, deployed within the Sichuan earthquake early warning network. EEW and JEEW issued their initial warning alerts 4.4 seconds and 8.2 seconds after the earthquake, respectively. The magnitude deviations were −1.6 and −0.8, while the epicenter location deviations were 11.2 km and 0.8 km, respectively. Over time and with increased data from additional monitoring stations, the early warning processing results eventually aligned with the findings of the official earthquake catalog. The earthquake early warning information had a blind area radius of 14.7 km. Outside this blind area, regions experiencing intensity level VI or higher were provided with warning times ranging from 0 to 21 seconds. The effectiveness of disaster mitigation was evident within the operational scope of the early warning system.
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表 1 台站主要安装仪器参数特征
Table 1. The specific parameter characteristics of the main instruments installed in the stations
台站类型 仪器名称 仪器型号 安装方式 量程 噪声 频带范围 基准站 宽频带地震计 GL-CS60 摆坑 0.01 m/s −170 dB@10 Hz
−180 dB@0.01 Hz0.016 7~80 Hz GL-CS120 摆坑 0.01 m/s −170 dB@10 Hz
−180 dB@0.01 Hz0.008 3~80 Hz 力平衡式加速度计 JS-A2 地面 2 g −130 dB DC~100 Hz 三分向加速度计 GL-A4 地面 2 g −130 dB DC~250 Hz(−3 dB) DC~150 Hz
(加速度响应平坦)基本站 力平衡式加速度计 JS-A2 地面 2 g −130 dB DC~100 Hz 一般站 MEMS加速度计 MEMS 地表 2 g −60~−110 dB DC~200 Hz以上 表 2 震中距100 km内数据缺失台站
Table 2. The stations with data missing within 100 km from the epicenter
震中距范围/km 台站总数 数据缺失台站 台站数 基准站 基本站 一般站 0~50 29 8 2 1 5 0~100 129 10 3 1 6 表 3 震中距100 km内触发台站延时
Table 3. Statistical delay triggering times for stations within 100 km from the epicenter
类别 延时/s ≤1.0 1.0~2.0 1.51~2.00 2.01~2.5 ≥2.5 三类台站数量 124 0 2 0 3 基准站数量 23 0 2 0 0 基本站数量 18 0 0 0 2 一般站数量 83 0 0 0 1 表 4 泸定M6.8地震EEW和JEEW预警处理结果(1~30次)
Table 4. EEW and JEEW early warning processing results of Luding M6.8 earthquake (1~30 times)
EEW地震预警产出 JEEW地震预警产出 处理
序号用时/s 触发
台站数纬度/(°N) 经度/(°E) 预警
震级定位
偏差/km处理
序号用时/s 触发
台站数纬度/(°N) 经度/(°E) 预警
震级定位
偏差/km1 3.9 3 29.64 102.18 4.1 10.7 第1报 8.2 19 29.59 102.09 6.0 0.8 第1报 4.4 5 29.64 102.18 5.2 11.2 2 9.3 23 29.59 102.09 6.0 0.5 3 4.9 5 29.64 102.18 5.4 11.2 3 10.1 27 29.59 102.07 6.5 0.6 4 5.5 7 29.57 102.07 5.9 2.0 4 10.7 34 29.59 102.08 6.4 0.2 5 6.0 10 29.58 102.08 5.7 1.1 5 11.4 39 29.59 102.08 6.3 0.4 6 6.5 10 29.58 102.08 6.1 1.1 6 11.6 40 29.59 102.07 6.3 0.6 7 7.0 12 29.58 102.08 6.0 1.1 7 12.3 50 29.59 102.09 6.3 0.9 8 7.6 13 29.59 102.09 6.2 1.1 8 13.2 53 29.60 102.09 6.3 1.1 9 8.1 14 29.59 102.09 6.6 1.1 9 13.5 56 29.59 102.09 6.4 1.2 10 8.5 16 29.59 102.09 6.5 1.1 10 14.2 59 29.59 102.09 6.3 1.1 11 9.1 18 29.59 102.09 6.3 1.1 11 14.6 65 29.60 102.09 6.3 1.5 12 9.6 19 29.59 102.08 5.9 0.4 12 15.3 71 29.60 102.09 6.3 1.4 13 10.2 24 29.59 102.09 6.7 1.1 13 16.3 82 29.60 102.09 6.3 1.5 14 10.7 28 29.59 102.09 6.7 1.1 14 17.3 91 29.60 102.10 6.3 1.6 15 11.2 34 29.60 102.09 6.7 1.2 15 19.4 114 29.60 102.09 6.3 1.3 16 11.7 39 29.59 102.08 6.8 0.4 16 20.5 132 29.60 102.09 6.4 1.5 17 12.2 44 29.60 102.08 6.5 0.7 17 20.9 133 29.60 102.09 6.4 1.5 18 12.9 49 29.60 102.09 6.8 1.2 18 21.8 144 29.60 102.09 6.4 1.4 19 13.7 56 29.60 102.10 6.7 1.8 19 22.7 156 29.60 102.09 6.4 1.5 20 14.6 65 29.60 102.10 6.8 1.8 20 23.6 168 29.60 102.09 6.4 1.5 21 15.2 71 29.60 102.10 6.8 1.8 21 24.3 170 29.60 102.09 6.4 1.5 22 15.9 76 29.60 102.10 6.7 1.8 22 25.1 184 29.59 102.09 6.4 1.4 23 16.9 84 29.60 102.10 6.8 1.8 23 25.6 190 29.60 102.09 6.4 1.4 24 17.4 86 29.60 102.10 6.8 1.8 24 26.6 211 29.59 102.09 6.4 1.4 25 18.1 91 29.60 102.10 6.8 1.8 25 27.1 218 29.59 102.09 6.4 1.4 26 19.2 100 29.60 102.10 6.8 1.8 26 28.2 229 29.59 102.09 6.4 1.3 27 20.7 112 29.60 102.10 6.8 1.8 27 28.8 240 29.59 102.09 6.3 1.3 28 23.4 130 29.60 102.10 6.8 1.8 28 29.7 251 29.59 102.09 6.3 1.2 29 31.9 165 29.60 102.10 6.8 1.8 29 30.5 262 29.59 102.09 6.3 1.2 30 31.6 273 29.60 102.10 6.8 1.8 30 31.2 283 29.59 102.09 6.3 1.1 表 5 地震预警系统理论处理时间参数含义
Table 5. The parameter explanation of theoretical processing time of earthquake early warning system
影响参数 下标含义 解释说明 影响因素 $ {\Delta }{{t}}_{{{\mathrm{a}}}} $ alert 地震预警理论处理时间 $ {\Delta }{{t}}_{{{\mathrm{s}}}}{、}{\Delta }{{t}}_{{{\mathrm{pa}}}}{、}{\Delta }{{t}}_{{{\mathrm{d}}}}{、}{\Delta }{{t}}_{{{\mathrm{h}}}}{、}{\Delta }{{t}}_{{{\mathrm{p}}}} $ $ {\Delta }{{t}}_{{{\mathrm{s}}}} $ station P波到达台站理论时间 台站密度 $ {}{\Delta }{{t}}_{{{\mathrm{pa}}}} $ pack 台站数据打包时间 地震监测仪器运行状态 $ {\Delta }{{t}}_{{{\mathrm{d}}}} $ delay 数据传输延迟时间 网络传输情况 $ {\Delta }{{t}}_{{{\mathrm{h}}}} $ handle 中心数据处理时间 预警软件及硬件平台性能 $ {\Delta }{{t}}_{{{\mathrm{p}}}} $ p-wave 所用数据的P波窗窗长 时钟准确度及波形记录质量 -
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