宋金^1,2,,
陈运泰^1,3,,,
张勇⁴
1. 中国地震局地球物理研究所, 北京 100081
2. 中国地震台网中心, 北京 100045
3. 中国科学院大学地球与行星科学学院, 北京 100049
4. 北京大学地球与空间科学学院, 北京 100871

基金项目: 国家重点研发计划（2018YFC1503705-4），国家自然科学基金（41822401）资助


详细信息

作者简介: 宋金, 女, 1986年生, 高工, 主要从事地震学研究.E-mail:songjinbent@163.com

通讯作者: 陈运泰, 男, 教授, 中国科学院院士, 主要从事地震学与地球物理学研究.E-mail:chenyt@cea-igp.ac.cn

中图分类号: P315

收稿日期:2020-02-14
修回日期:2020-07-02
上线日期:2020-09-05

Comparative study on the energy-moment ratio between the 2013 Minzhang earthquake and the 2014 Jinggu earthquake

SONG Jin^1,2,,
CHEN YunTai^1,3,,,
ZHANG Yong⁴
1. Institute of Geophysics, China Earthquake Administration, Beijing 100081, China
2. China Earthquake Networks Center, Beijing 100045, China
3. College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
4. School of Earth and Space Science, Peking University, Beijing 100871, China


More Information

Corresponding author: CHEN YunTai,E-mail:chenyt@cea-igp.ac.cn

MSC: P315

--> Received Date: 14 February 2020
Revised Date: 02 July 2020
Available Online: 05 September 2020


摘要
摘要:2013年岷漳地震和2014年景谷地震两个地震的矩震级均为M_W6.1，但相同等级烈度区域的面积差异显著，前者均明显大于后者.地面震动的强烈程度与震源破裂过程中辐射的地震波高频成分密切相关，作者系统地测定与研究了这两个地震的震源谱和反映其震源特征的能矩比等震源参量.结果表明，虽然岷漳地震和景谷地震释放的地震矩基本相同，分别为1.6×10¹⁸Nm和1.8×10¹⁸Nm，而且前者还比后者略小些，但其释放的地震波辐射能却差异显著，分别为1.3×10¹⁴J和0.6×10¹⁴J；因而前者的能矩比（8.1×10^-5）是后者能矩比（3.3×10^-5）的大约2.5倍.相应地，岷漳地震的视应力和应力降也都明显大于景谷地震的视应力和应力降.此外，这两个地震震源谱结果均显示出其高频趋势均按角频率ω的-2幂次衰减，符合"ω²模式"；采用理论震源谱公式计算结果分别约占实际结果的54%和50%，两个地震的地震波辐射能解析解之间的差异依然约2.3倍.震源破裂特征的显著差异导致岷漳地震单位地震矩释放的地震波辐射能更多，即岷漳地震能矩比更大，是导致这两个矩震级均为M_W6.1地震的地震烈度差异显著的一个重要原因.
关键词: 岷漳地震/
景谷地震/
等震线/
震源谱/
能矩比/
ω²模式

Abstract:The moment magnitude of the Minzhang earthquake in 2013 and the Jinggu earthquake in 2014 are both M_W6.1, but the former caused significantly larger area of the same isoseismals than the latter. The isoseismals of ground shaking is closely related to the high-frequency components of the seismic waves radiated during the source rupture. The source spectra of these two earthquakes and the energy-moment ratio which reflect the source characteristics, are measured and analyzed systematically. The results show that the seismic moment released by the Minzhang earthquake and Jinggu earthquake have little difference, 1.6×10¹⁸Nm and 1.8×10¹⁸Nm, respectively. The seismic moment of the Minzhang earthquake is slightly smaller than the seismic moment of the Jinggu earthquake, but the radiated energy of the Minzhang earthquake and Jinggu earthquake are 1.3×10¹⁴J and 0.6×10¹⁴J, respectively. Therefore the energy-moment ratio of the Minzhang earthquake (8.1×10^-5) is about 2.5 times that of the Jinggu earthquake (3.3×10^-5). Accordingly, the apparent stress and the stress drop of the Minzhang earthquake were significantly greater than that of the Jinggu earthquake. In addition, the modeling results of two earthquakes show that the high-frequency attenuation of source spectra are both consistent with ω² model. The radiated energy results calculated by the theoretical formula alone account for about 54% and 50% of the actual results respectively, and the difference of the theoretical radiated energy results between two earthquakes is still about 2.3 times. The significant difference of source rupture characteristics lead to different energy radiated per unit seismic moment. Minzhang earthquake has larger energy-moment ratio than the Jinggu earthquake, which is one of the important reasons resulting that the Minzhang earthquake is of larger isoseismal area than that of the Jinggu earthquake with the same isoseismal.
Key words:Minzhang earthquake/
Jinggu earthquake/
Isoseismal/
Source spectrum/
Energy-Moment ratio/
ω² model



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