【摘要】 2013年4月20日四川芦山MW6.7(MS7.0)地震发生后,中国地震台网中心(CENC)发布了地震速报参数.该文利用中国国家地震台网97个台站的资料对地震速报参数进行了修订,得出:四川芦山MW6.7地震的发震时刻为北京时间8时2分47.5秒(世界时间0时2分47.5秒),震中位置为30.30°N、102.99°E,震源深度17km.该地震的面波震级为MS7.0,短周期体波震级为mb6.0,中长周期体波震级为mB7.0;利用波形反演的方法计算了震源机制解,得到的最佳双力偶解的参数分别为节面Ⅰ:走向17°/倾角48°/滑动角80°;节面Ⅱ:走向212°/倾角43°/滑动角101°,矩震级为MW6.7.中国地震台网中心发布本次地震为面波震级MS7.0,而美国地质调查局(USGS)国家地震信息中心(NEIC)发布为矩震级MW6.6.为了消除这种差别,建议我国也应将矩震级作为对外发布的首选震级,使震级的发布与国际接轨.更多还原

【Abstract】 After the Lushan MW6.7(MS7.0) earthquake on 20 April,2013 in Sichuan Province,this paper revised the earthquake parameters rapidly issued by China Earthquake Networks Center(CENC),based on the data from 97 stations of China National Seismic Network.The results are:the origin time of theearthquake is 08:02:47.5 Beijing time(00:02:47.5UTC),the epicenter is located at (30.30°N,102.99°E) and the focal depth is 17km;the surface wave magnitude of the earthquake is MS7.0,the short period body wave magnitude is mb6.0 and the moderate-long period body wave magnitude is mB7.0.The focal mechanisms are calculated by waveform inversion and the two nodal planes of the best double couple solution are:for the nodal planeⅠ strike 17°/dip 48°/slip 80°,and strike 212°/dip 43°/slip 101°for the nodal planeⅡ;the moment magnitude is MW6.7.In addition,in view of the fact that the magnitude issued by CENC is MS7.0,while that by USGS/NEIC is MW6.6,so it is suggested that China should issue MW as the preferred magnitude so as to make the magnitude report in accordance with international convention.更多还原