Impact of dynamic stress on aftershock triggering of the 2021 Yunnan Yangbi MS6.4 earthquake
-
摘要: 选取IRIS远震台站波形数据，反演了云南漾濞MS6.4地震震源破裂过程，计算了断层破裂在近场产生的动态库仑破裂应力变化，并讨论了主震对近场余震活动的动态应力触发作用。结果显示：动态库仑应力演化过程与震源破裂特征反演结果一致，其大小分布与地震序列分布的疏密程度也具有较好的相关性。主震产生的静态和动态库仑破裂应力均促进余震的发生，但相比静态应力，余震位于库仑破裂应力正值区域的比例提高了21%，余震与动态库仑应力变化的正负区域有更好的一致性，动态应力能更好地解释震后余震分布的空间特征。垂直于地震序列主干10 km处出现小震丛集，该现象可能是由主震产生的动态库仑破裂应力占主导作用所致。定量分析主震对余震的动态应力触发结果显示，主震后一周内MS4.0以上的8次余震接收点均受到了动态库仑破裂应力的触发作用。Abstract: Based on the waveform data of IRIS teleseismic station, this paper inversed the focal rupture process of Yunnan Yangbi MS6.4 earthquake, calculated the dynamic Coulomb rupture stress change caused by fault rupture in near field and discussed the dynamic stress triggering effect of main shock on near-field aftershock activity. The results show that the evolution process of dynamic Coulomb stress is consistent with the inversion results of source fracture characteristics, and its size distribution is also well correlated with the density of seismic sequence distribution. The static and dynamic Coulomb rupture stress produced by the main shock promote the occurrence of aftershocks, but compared with the static stress, the proportion of aftershocks located in the positive Coulomb rupture stress area is increased by 21%, and the positive and negative areas of aftershocks and dynamic Coulomb stress change have better consistency. The dynamic stress can better explain the spatial characteristics of aftershocks distribution after the earthquake. Small earthquakes cluster at 10 km perpendicular to the main trunk of the earthquake sequence, which may be caused by the dominant dynamic Coulomb fracture stress produced by the main earthquake. Quantitative analysis of the dynamic stress triggering of the main shock to the aftershock shows that within one week after the main shock, eight aftershocks receiving points bigger than MS4.0 are triggered by the dynamic Coulomb rupture stress.
-
图 1 云南漾濞MS6.4地震震中区构造背景（a）、地震序列空间分布（b）及剖面上的投影（c）
Figure 1. Tectonic setting （a） of the epicentral area and spatial distribution （b） for Yunnan Yangbi MS6.4 earthquake sequence and its projection on profile （c）
图 2 台站分布和P波垂向位移理论图（红线）与观测波形（黑线）的拟合情况（a）以及每2秒破裂快照（b）
Figure 2. Station distribution and the fitting of P-wave vertical displacement theoretical graph （red line） and observed waveform （black line） （a） and snapshot shown every 2 s （b）
图 3 云南漾濞MS6.4地震静态应力变化（a）和地震序列密度分布及MS4.0以上余震震源机制（b）
Figure 3. Static stress change of the Yunnan Yangbi MS6.4 earthquake （a） and density distribution of the earthquake sequence and focal mechanisms of aftershocks above MS4.0
4 ∆CFS动态演化
图中百分数表示余震位于动态库仑破裂应力正值区域的比例
4. Dynamic evolution of ∆CFS
The percentage in the figure shows the proportion of aftershocks in the positive value area of dynamic Coulomb stress
图 4 ∆CFS动态演化
图中百分数表示余震位于动态库仑破裂应力正值区域的比例
Figure 4. Dynamic evolution of ∆CFS
The percentage in the figure shows the proportion of aftershocks in the positive value area of dynamic Coulomb stress
表 1 云南漾濞MS6.4地震震源参数
Table 1. Focal mechanism parameters of the Yunnan Yangbi MS6.4 earthquake
发震日期 震中位置 MW 深度/km 节面Ⅰ 节面Ⅱ 来源 年-月-日 北纬/° 东经/° 走向/° 倾角/° 滑动角/° 走向/° 倾角/° 滑动角/° 25.61 100.02 6.1 15.0 46 78 4 315 86 168 GCMT （2021） 2021-05-21 25.73 100.01 6.1 9.0 135 82 −165 43 75 −9 USGS （2021） 25.69 99.88 5.9 7.8 135 75 −168 42 78 −15 重定位（龙锋等，2021） 
下载: 导出CSV
表 2 云南漾濞MS6.4地震震源附近地壳分层模型
Table 2. Crustal layered model near the seismic source of the Yunnan Yangbi MS6.4 earthquake
深度/km vP/（km·s−1） vS/（km·s−1） 地壳密度/（g·cm−3） QP QS 0 7.75 4.47 3.37 600 300 4 4.85 2.80 3.37 600 300 16 6.25 3.61 3.37 600 300 22 6.40 3.70 3.37 600 300
下载: 导出CSV
表 3 主震对MS≥4.0余震应力触发情况
Table 3. The stress trigger of the main shock to MS≥4.0 aftershocks
地震序号 与主震震中的
距离/km开始变化
时间/s达到峰值
时间/s∆CFS峰值
/MPa趋于稳定
时间/s稳定值
/MPa应力触发 1 8.67 2.0 3.7 0.13 13 0.09 动态、静态应力触发 2 12.68 1.7 5.3 0.83 16 −0.001 动态应力触发 3 13.49 2.0 5.3 0.47 13 0.01 动态应力触发，静态应力可能触发 4 13.49 1.9 5.7 0.27 14 −0.02 动态应力触发 5 2.22 3.0 3.5 0.39 动态应力触发 6 1.00 1.8 8.4 0.50 12 0.48 动态、静态应力触发 7 8.98 2.0 7.4 0.12 11 0.09 动态、静态应力触发 8 11.17 5.0 7.5 0.18 13 0.02 动态应力触发，静态应力可能触发
下载: 导出CSV
-
常祖峰,常昊,李鉴林,代博洋,周青云,朱家龙,罗宗其. 2016. 维西—乔后断裂南段正断层活动特征[J]. 地震研究,39(4):579–586. doi: 10.3969/j.issn.1000-0666.2016.04.007 Chang Z F,Chang H,Li J L,Dai B Y,Zhou Q Y,Zhu J L,Luo Z Q. 2016. The characteristic of active normal faulting of the southern segment of Weixi−Qiaohou fault[J]. Journal of Seismological Research,39(4):579–586 (in Chinese). 郝平,刘杰,韩竹军,傅征祥. 2006. 印尼MS8.7地震对中国大陆3次后续中强地震的动应力触发研究[J]. 地震,26(3):26–36. Hao P,Liu J,Han Z J,Fu Z X. 2006. Dynamic stress triggering of three subsequent moderately strong earthquakes in China’s mainland following the Indonesia MS8.7 earthquake[J]. Earthquake,26(3):26–36 (in Chinese). 冀战波,王琼,王海涛,解朝娣. 2014. 2008年新疆于田MS7.3地震对后续地震的完全库仑应力触发作用[J]. 地震学报,36(6):997–1009. Ji Z B,Wang Q,Wang H T,Xie C D. 2014. Impact of complete Coulomb failure stress changes of the 2008 Xinjiang Yutian MS7.3 earthquake on the subsequent earthquakes[J]. Acta Seismologica Sinica,36(6):997–1009 (in Chinese). 李传友,张金玉,王伟,孙凯,单新建. 2021. 2021年云南漾濞 6.4 级地震发震构造分析[J]. 地震地质,43(3):706–721. doi: 10.3969/j.issn.0253-4967.2021.03.015 Li C Y,Zhang J Y,Wang W,Sun K,Shan X J. 2021. The seismogenic fault of the 2021 Yunnan Yangbi MS6.4 earthquake[J]. Seismology and Geology,43(3):706–721 (in Chinese). 龙锋,祁玉萍,易桂喜,吴微微,王光明,赵小艳,彭关灵. 2021. 2021年5月21日云南漾濞MS6.4地震序列重新定位与发震构造分析[J]. 地球物理学报,64(8):2631–2646. Long F,Qi Y P ,Yi G X,Wu W W,Wang G M,Zhao X Y,Peng G L. 2021. Relocation of the MS6.4 Yangbi earthquake sequence on May 21,2021 in Yunnan Province and its seismogenic structure analysis[J]. Chinese Journal of Geophysics,64(8):2631–2646 (in Chinese). 缪淼,朱守彪. 2013. 2013年芦山MS7.0地震产生的静态库仑应力变化及其对余震空间分布的影响[J]. 地震学报,35(5):619–631. Miao M,Zhu S B. 2013. The static Coulomb stress change of the 2013 Lushan MS7.0 earthquake and its impact on the spatial distribution of aftershocks[J]. Acta Seismologica Sinica,35(5):619–631 (in Chinese). 缪淼,朱守彪. 2016. 2014年鲁甸地震(MS=6.5)静态库仑应力变化及其影响[J]. 地震地质,38(1):169–181. Miao M ,Zhu S B. 2016. The static Coulomb stress change of the 2014 Ludian earthquake and its influence on the aftershocks and surrounding faults[J]. Seismology and Geology,38(1):169–181 (in Chinese). 潘睿,姜金钟,付虹,李姣. 2019. 2017年云南漾濞MS5.1及MS4.8地震震源机制解和震源深度测定[J]. 地震研究,42(3):338–348. doi: 10.3969/j.issn.1000-0666.2019.03.005 Pan R,Jiang J Z,Fu H,Li J. 2019. Focal mechanism and focal depth determination of Yunnan Yangbi MS5.1 and MS4.8 earthquakes in 2017[J]. Journal of Seismological Research,42(3):338–348 (in Chinese). 盛书中,万永革,蒋长胜,卜玉菲. 2015. 2015年尼泊尔MS8.1强震对中国大陆静态应力触发影响的初探[J]. 地球物理学报,58(5):1834–1842. Sheng S Z,Wan Y G,Jiang C S,Bu Y F. 2015. Preliminary study on the static stress triggering effects on China mainland with the 2015 Nepal MS8.1 earthquake[J]. Chinese Journal Of Geophysics,58(5):1834–1842 (in Chinese). 王琼,解朝娣,冀战波,刘建明. 2016. 2014年于田MS7.3地震对后续余震和远场小震活动的动态应力触发[J]. 地球物理学报,59(4):1383–1393. Wang Q,Xie C D,Ji Z B,Liu J M. 2016. Dynamically triggered aftershock activity and far-field microearthquakes following the 2014 MS7.3 Yutian,Xinjiang earthquake[J]. Chinese Journal of Geophysics,59(4):1383–1393 (in Chinese). 吴建平,明跃红,王椿镛. 2004. 云南地区中小地震震源机制及构造应力场研究[J]. 地震学报,26(5):457–465. doi: 10.3321/j.issn:0253-3782.2004.05.001 Wu J P,Ming Y H,Wang C Y. 2004. Source mechanism of small-to-moderate earthquakes and tectonic stress field in Yunnan Province[J]. Acta Seismologica Sinica,26(5):457–465 (in Chinese). 许才军,汪建军,熊维. 2018. 地震应力触发回顾与展望[J]. 武汉大学学报信息科学版,43(12):2085–2092. Xu C J,Wang J J,Xiong W. 2018. Retrospection and perspective for earthquake stress triggering[J]. Geomatics and Information Science of Wuhan University,43(12):2085–2092 (in Chinese). 杨智娴,于湘伟,郑月军,陈运泰,倪晓晞,Chan W. 2004. 中国中西部地区地震的重新定位和三维地壳速度结构[J]. 地震学报,26(1):19–19. doi: 10.3321/j.issn:0253-3782.2004.01.003 Yang Z X,Yu X W,Zheng Y J,Chen Y T,Ni X X,Chan W. 2004. Earthquake relocation and 3-dimensional crustal structure of P-wave velocity in central-western China[J]. Acta Seismologica Sinica,26(1):19 (in Chinese). 赵立波,赵连锋,谢小碧,曹俊兴,姚振兴. 2016. 2014年2月12日新疆于田MW7.0地震源区静态库仑应力变化和地震活动率[J]. 地球物理学报,59(10):3732–3743. Zhao L B,Zhao L F,Xie X B,Cao J X,Yao Z X. 2016. Static Coulomb stress changes and seismicity rate in the source region of the 12 February,2014 MW7.0 Yutian earthquake in Xinjiang,China[J]. Chinese Journal of Geophysics,59(10):3732–3743 (in Chinese). Bouchon M. 1981. A simple method to calculate Green’s functions for elastic layered media[J]. Bull Seism Soc Am,71(4):959–971. Bouchon M. 2003. A review of the discrete wavenumber method[J]. Pure Appl Geophys,160(3):445–465. Brodsky E E,Karakostas V,Kanamori H. 2000. A new observation of dynamically triggered regional seismicity:Earthquakes in Greece following the August 1999 Izmit,Turkey earthquake[J]. Geophys Res Lett,27(1):2741–2744. Cotton F,Coutant O. 1997. Dynamic stress variations due to shear faults in a plane-layered medium[J]. Geophys J Int,128(3):676–688. GCMT. 2021. 202105211348A Yunnan, China[DB/OL]. [2021-05-28]. https://www.globalcmt.org/. Harris R A. 1998. Introduction to special section:Stress triggers,stress shadows,and implications for seismic hazard[J]. J Geophys Res:Solid Earth,103(B10):24347–24358. doi: 10.1029/98JB01576 Hartzell S H,Heaton T H. 1983. Inversion of strong ground motion and teleseismic waveform data for the fault rupture history of the 1979 Imperial Valley,California,earthquake[J]. Bull Seism Soc Am,73(6A):1553–1583. Hill D P,Reasenberg P A,Michael A,Arabaz W J,Beroza G,Brumbaugh D,Brune J N,Castro R,Davis S,Depolo D,Ellsworth W L,Gomberg J,Harmsen S,House L,Jackson S M,Johnston M J S,Jones L,Keller R,Malone S,Munguia L,Nava S,Pechmann J C,Sanford A,Simpson R W,Smith R B,Stark M,Stickney M,Vidal A,Walter S,Wong V,Zollweg J. 1993. Seismicity remotely triggered by the magnitude 7.3 Landers,California,earthquake[J]. Science,260(5114):1617–1623. doi: 10.1126/science.260.5114.1617 Kilb D,Gomberg J,Bodin P. 2000. Triggering of earthquake aftershocks by dynamic stresses[J]. Nature,408:570–574. Meyer M,Kearnes K. 2013. Introduction to special section:Intermediaries between science,policy and the market[J]. Sci Public Policy,40(4):423–429. Mohamad R,Darkal A N,Seber D,Sandvol E,Gocuez F,Barazangi M. 2000. Remote earthquake triggering along the Dead Sea fault in Syria following the 1995 Gulf of Aqaba earthquake (MS=7.3)[J]. Seismological Research Letters,71(1):47–52. doi: 10.1785/gssrl.71.1.47 Muller G. 1985. The reflectivity method:A tutorial[J]. J Geophys Int,58(1/2/3):153–174. Okada Y. 1992. Internal deformation due to shear and tensile faults in a half-space[J]. Bull Seism Soc Am,82(2):1018–1040. doi: 10.1785/BSSA0820021018 Pollitz F F,Sacks I S. 1997. The 1995 Kobe,Japan,earthquake:A long-delayed aftershock of the offshore 1944 Tonankai and 1946 Nankaido earthquakes[J]. Bull Seisml Soc Am,87(1):1–10. Reasenberg P A,Simpson R W. 1992. Response of regional seismicity to the static stress change produced by the Loma-Prieta earthquake[J]. Science,255(5052):1687–1690. doi: 10.1126/science.255.5052.1687 Steacy S,Nalbant S S,Mccloskey J,Nostro C,Scotti O,Baumont D. 2005. Onto what planes should Coulomb stress perturbations be resolved?[J]. J Geophys Res,110(B5):B05S15. Stein R S,King G C,Lin J. 1994. Stress triggering of the 1994 M6.7 Northridge,California,earthquake by its predecessors[J]. Science,265(5177):1432–1435. doi: 10.1126/science.265.5177.1432 Toda S,Stein R S,Reasenberg P A,Dieterich J H,Yoshida A. 1998. Stress transferred by the 1995 MW6.9 Kobe,Japan,shock:Effect on aftershocks and future earthquake probabilities[J]. J Geophys Res:Solid Earth,103(B10):24543–24565. doi: 10.1029/98JB00765 USGS. 2021. M6.1: 25 km NW of Dali, China[DB/OL]. [2021-05-28]. https://earthquake.usgs.gov/earthquakes/eventpage/us7000e532/moment-tensor. Wu C Q,Peng Z G,Wang W J,Chen Q F. 2011. Dynamic triggering of shallow earthquakes near Beijing,China[J]. Geophys J Int,185(3):1321–1334. -
查看大图
图(6) / 表(3)
计量
- 文章访问数: 246
- HTML全文浏览量: 119
- PDF下载量: 107
- 被引次数: 0