学术
Comparison between different earthquake magnitudes determined by China Seismograph Network
刘瑞丰[1,2] 陈运泰[2] 任枭[1] 徐志国[1] 孙丽[1] 杨辉[1] 梁建宏[1] 任克新[1]
[1]China Earthquake Networks Center,Beijing 100045,China [2]Institute of Geophysics,China Earthquake Administration,Beijing 100081,China
文章出处:
《地震学报：英文版》-2007年20卷5期 -497-506页
栏目信息:
分 类 号:
文献标识码:
A
文章编号:
1000-9116（2007）05-0497-10
相关文章:
Comparison between different earthquake magnitudes determined by China Seismograph Network
LIU Rui feng , CHEN Yun tai, REN Xiao, XUZhi guo, SUNLi,YANGHui, LIANG Jian hong, REN Ke xin（1. China Earthquake Networks Center, Beijing 100045, China; 2.Institute of Geophysics, China Earthquake Administration, Beijing 100081, China）
Abstract:
By linear regression and orthogonal regression methods, comparisons are made between different magnitudes （local magnitude ML, surface wave magnitudes Ms and MsT, long-period body wave magnitude mB and short-period body wave magnitude mb） determined by Institute of Geophysics, China Earthquake Administration, on the basis of observation data collected by China Seismograph Network between 1983 and 2004. Empirical relations between different magnitudes have been obtained. The result shows that： ① As different magnitude scales reflect radiated energy by seismic waves within different periods, earthquake magnitudes can be described more objectively by using different scales for earthquakes of different magnitudes. When the epicentral distance is less than 1000 km, local magnitude ME can be a preferable scale; In case M〈4.5, there is little difference between the magnitude scales; In case 4.5〈M〈6.0, mB〉Ms, i.e., Ms underestimates magnitudes of such events, therefore, mB can be a better choice; In case M〉6.0, Ms〉mB〉mb, both mB and mb underestimate the magnitudes, so Ms is a preferable scale for determining magnitudes of such events （6.0〈M〈8.5）; In case M〉8.5, a saturation phenomenon appears in Ms, which cannot give an accurate reflection of the magnitudes of such large events; ② In China, when the epicentral distance is less than 1 000 km, there is almost no difference between ME and Ms, and thus there is no need to convert between the two magnitudes in practice; ③ Although Ms and Ms7 are both surface wave magnitudes, Ms is in general greater than Ms7 by 0.2～0.3 magnitude, because different instruments and calculation formulae are used; ④ mB is almost equal to mb for earthquakes around mB4.0, but mB is larger than mb for those of mB〉4.5, because the periods of seismic waves used for measuring mB and mb are different though the calculation formulae are the same.[著者文摘]
Key words:
local earthquake magnitude; surface wave magnitude; body wave magnitude
基金资助:
Special Project on Earthquake from Ministry of Science and Technology of China. Acknowledgements We express my sincere thanks to Prof. Peter Bormann in Germany＇s National Research Centre for Geosciences and Dr. Diethelm Kaiser in Federal Institute forGeodcienes and Natual Resources for the helps in method and software.
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