云南地震台网与中国地震台网、美国地震台网测定震级的对比

利用云南地震台网全面数字化之后(2008-2017年)的记录资料,按照《地震震级的规定》(GB17740-2017)规定的测定方法,对云南地震台网记录的ML≥4. 0地震,重新人工测量其宽频带面波震级MS(BB)和矩震级Mw,与中国地震台网测定的MS7以及美国地震台网(NEIC)测定的MW(NEIC)进行对比分析。结果表明:①MS(BB)和MS7测量方法相同,量规函数相等,两者一致性最好。②对于面波震级与矩震级,当MW在3. 5左右时,MS7,MS(BB)与MW一致性最好;MW<3. 5时,MS7和MS(BB)均小于MW;MW> 3. 5时,MS7和MS(BB)大于MW。③MS(BB)与美国地震台网相比较,MS(BB)在5. 5和6. 0左右时,与MW(NEIC)一致性最好,几乎相等;MS(BB)<5. 5时,MS(BB) 6. 0时,MS(BB)> MW(NEIC)。④MW和MW(NEIC)之间存在偏差,MW整体小于MW(NEIC)。

Comparison of Determination of Magnitudes between Yunnan Seismic Network and National Seismic Network and American Seismic Network

Using the data which recorded by the Yunnan Seismic Network after fully complete the digitization(2008-2017),in accordance with the determination method specified by the new magnitude national standard 《Earthquake magnitude provisions》(GB17740-2017),for the earthquakes of magnitude greater than ML4. 0,we manual remeasured the wide band surface wave magnitude MS(BB)and the moment magnitude Mw,and compared with the MS7 of the National Network cataloguing results and the MW(NEIC)measured by the United States Seismic Network(NEIC),the results show that: the measurement method of MS(BB)and MS7 are the same,the gauge functions are equal,the consistency of the two is the best. The surface wave magnitude and moment magnitude have the system difference,and MS7,MS(BB)and MW are almost equal when the magnitude is around MW3. 5. For the moment magnitude less than 3. 5,MS7 and MS(BB)are less than MW,while for the moment magnitude more than 3. 5,MS7 and MS(BB)are greater than MW. Compared with the United States Seismic Network,when MS(BB)is about 5. 5 and 6. 0,MS(BB)and MW(NEIC)have the best consistency,and the two are almost equal. When MS(BB)is less than 5. 5,MS(BB)is smaller than MW(NEIC),while MS(BB)is greater than MW(NEIC)when it is greater than 6. 0. There is a system deviation between MW and MW(NEIC),MW is less than MW(NEIC)overall,and with the increase of the magnitude,the deviation value is on the rise.