2021年云南漾濞MS6.4地震预警处理结果分析
李丹宁,张国权,缪素秋,高 洋,秦 敏,马红虎,崔庆谷

(云南省地震局,云南 昆明 650224)

地震预警; 台站类别; 震级偏差; 漾濞MS6.4地震

Analysis of Early Warning Processing Results from the 2021 Yangbi,Yunnan MS6.4 Earthquake
LI Danning,ZHANG Guoquan,MIAO Suqiu,GAO Yang,QIN Min,MA Honghu,CUI Qinggu

(Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)

earthquake early warning; stations type; magnitude error; the Yangbi MS6.4 earthquake

备注

2021年5月21日云南漾濞发生MS6.4地震,云南地震预警处理系统对观测数据进行了有效处理并产出预警信息。首先分析了观测记录的走时—震中距关系以及不同类型台站的信噪比,说明该系统震相拾取正确,确保了震中位置和发震时刻测定的高准确度; 鉴于此次地震预警震级整体偏小,对比了不同类型台站的震级偏差,其中一般台震级偏差最小、测震台次之、基准台第三、基本台最大。云南地震预警处理系统在2021年5月接入基准台和基本台后,对于漾濞地震的震中位置和发震时刻测定的准确性和稳定性均有提高,震级偏差变化不明显,仍然整体偏小。这说明了云南地震预警处理系统台站布局合理,系统具备一定的预警能力,但震级算法还有待改进。
On May 21,2021,the Yunnan Earthquake Early Warning Processing System effectively processed the Yangbi MS6.4 earthquake and produced kinds of early warning information.This paper analyzed the relationship between the arrival time and the epicentral distance.It is found that for the Yangbi earthquake,the Early Warning System picked up seismic phases without mistake,ensuring high accuracy of the epicenter location and the origin time.The magnitude given by the system is generally underestimated.We compared the magnitude error of different types of stations,and found that the stations deployed with seismic-intensity meters have the smallest error,followed by the old seismometer stations and the newly-built seismometer stations.The accelerometer stations have the largest error.The Early Warning Processing System was connected to the newly-built seismometer stations and the accelerometer stations in May 2021,which in favor of improving the accuracy and stability of early warning results like the epicenter location and the original time of the Yangbi earthquake given by the system.But the magnitude error has not changed significantly,and the magnitude is still generally underestimated.This proves that the stations' layout of the Yunnan Earthquake Early Warning Processing System is reasonable; the epicenter and the origin time produced by the system are of high accuracy.The system has a certain early warning capability,but its magnitude algorithm needs to be improved.