矩震级及震源机制相似地震的辐射能量差别——2014年鲁甸地震与景谷地震宽频带体波震级的比较

Difference in energy radiation from earthquakes with similar moment magnitude and focal mechanism—A comparison of the broadband body-wave magnitudes of the 2014 Ludian and Jinggu earthquake

摘要:

2014年8月3日鲁甸地震和10月7日景谷地震具有相似的矩震级和震源机制，但所造成的灾害却相差甚远。为考察地震辐射能量在这两次地震致灾过程中的作用，本文利用震中距6°~80°范围内记录了鲁甸地震的142个台站、记录了景谷地震的138个台站的宽频带地震记录，计算了累积宽频带体波震级m_Bc。结果表明鲁甸地震的m_Bc高于景谷地震，因此地震辐射能量的差别对解释两次地震灾害的差别有不可忽视的作用。

Abstract:

In spite of the similar moment/surface wave magnitude and similar near-vertical strike-slip faulting,the August 3,2014,Ludian,Yunnan,M_S6.5/M_W6.2 earthquake and the October 7,2014,Jinggu,Yunnan,M_S6.6/M_W6.1 earthquake caused sharply different disasters,the former having a fatality/missing up to about 700 and injury about 3,000,and the latter fatality 1 and injury about 300. To investigate the role of seismic radiated energy in such a difference,we analyzed 142 broadband(BB)vertical recordings of the Ludian earthquake and 138 BB vertical recordings of the Jinggu earthquake,with epicentral distance 6°~80°,and calculated the broadband cumulative body-wave magnitude m_Bc. It is shown that the m_Bc of the Ludian earthquake is about 0.3 higher than the Jinggu earthquake,indicating that radiated energy contributes significantly to the difference of the earthquake disasters.