地震研究

采用能够综合协调长期变形和震后短期变形的Burgers流变模型,模拟了1976年唐山强震群引起的震后形变场以及同震和震后库仑应力变化。结果显示:1976年唐山强震群中主震的两个破裂面以及滦县和宁河两次强余震均对2020年古冶5.1级地震表现为库仑应力加载。岩石圈粘弹性松弛效应引起的库仑应力变化显示,震后15年前后,库仑应力演化状态呈现显著的差异性:震后15年内,库仑应力变化剧烈; 而震后15年后,库仑应力呈现缓慢的稳定增加状态。该过程与唐山强震群余震区地震活动过程相似,可能暗示1976年唐山强震群余震区应力调整过程已基本稳定。

Based on the Burgers rheological model which is absorbed in the synthetic simulation of long-term tectonic deformation and short-term postseismic deformation,we simulated the co- and postseismic deformation and the related coseismic and postseismic Coulomb stress evolution that caused by the 1976 Tangshan strong earthquake swarm.Our results show that the two segements of mainshock rupture and the two strong aftershocks in Luanxian and Ninghe of 1976 Tangshan strong earthquake swarm could enhance the Coulomb stress on the rupture plane of the 2020 Guye M5.1 earthquake.The temporal evolution of the lithosphere postseismic relaxation Coulomb stress show that,before and after the postseismic 15 years,the evolution state of Coulomb stress shows significant difference.Within 15 years after the Tangshan earthquake,the Coulomb stress evolution is dramatic,and while after 15 years,it is increased steady and slowly.This pattern is similar to the seismicity in the aftershock zone of Tangshan strong earthquake swarm.This may indicated that the dynamic stress adjustment in the aftershock zone of Tangshan strong earthquake swarm have been stabilization.

引言
1 模型建立
2 计算结果
3 讨论
4 结论

图1 Burgers流变模型(a)及其与Maxwell体和Kelvin体的变形模式对比(b)(据Caron et al,2014)<br/>Fig.1 Diagram of Burgers rheology(a)and its deformation mechanism that compare with Maxwell and Kelvin rheologies(b)(based on Caron et al,2014)

图1 Burgers流变模型(a)及其与Maxwell体和Kelvin体的变形模式对比(b)(据Caron et al,2014)
Fig.1 Diagram of Burgers rheology(a)and its deformation mechanism that compare with Maxwell and Kelvin rheologies(b)(based on Caron et al,2014)

表1 岩石圈介质模型参数<br/>Tab.1 Mechanical properties of the Lithosphere

表1 岩石圈介质模型参数
Tab.1 Mechanical properties of the Lithosphere

图2 1976年唐山强震群附近构造及余震活动时空分布<br/>Fig.2 Geological structure and aftershocks distribution around the 1976 Tangshan earthquake swarm area

图2 1976年唐山强震群附近构造及余震活动时空分布
Fig.2 Geological structure and aftershocks distribution around the 1976 Tangshan earthquake swarm area

表2 唐山强震群同震位错模型<br/>Tab.2 Coseismic dislocation model of the Tangshan strong earthquake swarm

表2 唐山强震群同震位错模型
Tab.2 Coseismic dislocation model of the Tangshan strong earthquake swarm

表3 唐山强震群对古冶地震的同震库仑应力加载<br/>Tab.3 Coseismic Coulomb stress loading of Tangshan strong earthquake swarm on Guye earthquake

表3 唐山强震群对古冶地震的同震库仑应力加载
Tab.3 Coseismic Coulomb stress loading of Tangshan strong earthquake swarm on Guye earthquake

图3 唐山强震群对古冶地震的震后库仑应力加载时间演化<br/>Fig.3 Temporal evolution of the postseismic Coulomb stress loading of Tangshan strong earthquake swarm on Guye earthquake

图3 唐山强震群对古冶地震的震后库仑应力加载时间演化
Fig.3 Temporal evolution of the postseismic Coulomb stress loading of Tangshan strong earthquake swarm on Guye earthquake

图4 唐山地震主震-1(a),主震-2(b),和滦县(c),宁河(d)2次余震对古冶地震的应力作用<br/>Fig.4 Stress loading of the Mainshock-1(a),Mainshock-2(b)of Tangshan earthquake,Luanxian aftershock(c),Ninghe aftershock(d)on Guye earthquake

图4 唐山地震主震-1(a),主震-2(b),和滦县(c),宁河(d)2次余震对古冶地震的应力作用
Fig.4 Stress loading of the Mainshock-1(a),Mainshock-2(b)of Tangshan earthquake,Luanxian aftershock(c),Ninghe aftershock(d)on Guye earthquake

图5 有效摩擦系数分别为0.1(a),0.4(b),0.7(c)时对古冶地震断层面库仑应力的影响<br/>Fig.5 Impact of the effective friction coefficient of 0.1(a),0.4(b),0.7(c)on the Coulomb stress loading on the fault plane of Guye earthquake

图5 有效摩擦系数分别为0.1(a),0.4(b),0.7(c)时对古冶地震断层面库仑应力的影响
Fig.5 Impact of the effective friction coefficient of 0.1(a),0.4(b),0.7(c)on the Coulomb stress loading on the fault plane of Guye earthquake

图6 唐山强震群余震活动(a)及其能量蠕变(b)和累积频度(c)曲线<br/>Fig.6 Aftershock activity of the Tangshan strong earthquake swarm(a)and the corresponding energy creeping(b) and cumulated frequentness(c)

图6 唐山强震群余震活动(a)及其能量蠕变(b)和累积频度(c)曲线
Fig.6 Aftershock activity of the Tangshan strong earthquake swarm(a)and the corresponding energy creeping(b) and cumulated frequentness(c)

楚全芝,汪良谋.1994.华北地区构造应力场、断层滑动速率与强震的关系[J].华北地震科学,12(1):9-20.
虢顺民,李志义,程绍平,等.1977.唐山地震区域构造背景和发震模式的讨论[J].地质科学,(4):305-321.
贾若,蒋海昆.2014.基于同震库仑应力变化的汶川地震余震频次研究[J].中国地震,30(1):74-90.
蒋长胜,吴忠良,庄建仓.2013.地震的“序列归属”问题与ETAS模型——以唐山序列为例[J].地球物理学报,56(9):2971-2981,doi:10.6038/cjg20130911.
刘桂萍,傅征祥.2002.1973 年炉霍大地震(MS=7.6)最大余震(MS=6.3)的库仑破裂应力触发[J].中国地震,18(2):175-182.
柳畅,石耀霖,郑亮,等.2012.三维黏弹性数值模拟华北盆地地震空间分布与构造应力积累关系[J].地球物理学报,55(12):3942-3957.
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.
单斌,李佳航,韩立波,等.2012.2010年MS7.1级玉树地震同震库仑应力变化以及对2011年MS5.2级囊谦地震的影响[J].地球物理学报,55(9):3028-3042,doi:10.6038/j.issn.0001-5733.2012.09.021.
邵志刚,傅容珊,薛霆虓,等.2007.以Burgers体模型模拟震后粘弹性松弛效应[J].大地测量与地球动力学,27(5):31-37.
邵志刚,傅容珊,薛霆虓,等.2009.库仑应力变化与余震对应关系的初步探讨——以集集地震为例[J].地球物理学进展,24(2):367-374.
沈正康,万永革,甘卫军,等.2004.华北地区700年来地壳应力场演化与地震的关系研究[J].中国地震,20(3):211-228.
石富强,朱琳,王莹,等.2017.九寨沟MS7.0地震对巴颜喀拉块体东北缘活动断裂影响的有限元模拟[J].中国地震,33(4):463-470.
孙荀英,刘激扬,王仁.1994.1976年唐山地震震时和震后变形的模拟[J].地球物理学报,37(1):45-55.
万永革,沈正康,刁桂苓,等.2008a.利用小震分布和区域应力场确定大震断层面参数方法及其在唐山地震序列中的应用[J].地球物理学报,51(3):793-804.
万永革,沈正康,曾跃华,等.2008b.唐山地震序列应力触发的粘弹性力学模型研究[J].地震学报,30(6):581-593.
万永革,万永魁,靳志同,等.2017.用形变资料反演1976年唐山地震序列的破裂分布[J].地球物理学报,60(9):3378-3395,doi:10.6038/cjg2017M0909.
万永革.2019.同一地震多个震源机制中心解的确定[J].地球物理学报,62(12):4718-4728,doi:10.6038/cjg2019M0553.
闻学泽,马胜利.2006.唐山大地震对相邻断裂段地震复发的影响[J].自然科学进展,16(10):1346-1350.
徐伟进,高孟潭.2014.中国大陆及周缘地震目录完整性统计分析[J].地球物理学报,57(9):2802-2812,doi:10.6038/cjg 20140907.
尤惠川,徐锡伟,吴建平,等.2002.唐山地震深浅构造关系研究[J].地震地质,24(4):571-582.
张群伟,朱守彪.2019.华北地区主要断裂带上的库仑应力变化及地震活动性分析[J].地震地质,41(3):649-669.
张素欣,边庆凯,张子广,等.2020.唐山断裂北段地震分布特征及其构造意义[J].地震研究,43(2):270-277.
Broerse T,Riva R,Simons W,et al.2015.Postseismic GRACE and GPS observations indicate a rheology contrast above and below the Sumatra slab[J].Journal of Geophysical Research:Solid Earth,120(7):5343-5361.
Caron L,Greff M,Fleitout L,et al.2014.Effect of Burgers Rheology in glacial isostatic adjustment models[C].Vienna,Austria:EGU General Assembly Conference Abstracts.
Harris R A.1998.Introduction to special section:Stress triggers,stress shadows,and implications for seismic hazard[J].Journal of Geophysical Research:Solid Earth,103(B10):24347-24358.
Hergert T,Heidbach O.2011.Geomechanical model of the Marmara Sea region—II.3-D contemporary background stress field[J].Geophysical Journal International,185(3):1090-1102.
Huang B S,Yeh Y T.1997.The fault ruptures of the 1976 Tangshan earthquake sequence inferred from coseismic crustal deformation[J].Bulletin of the Seismological Society of America,87(4):1046-1057.
Huang M,Bürgmann R,Freed A M.2014.Probing the lithospheric rheology across the eastern margin of the Tibetan Plateau[J].Earth and Planetary Science Letters,396(15):88-96.
Jaeger J C,Cook N G W,Zimmerman R.2009.Fundamentals of rock mechanics[M].Hoboken:John Wiley & Sons Inc,90.
King G C,Stein R S.Lin J.1994.Static stress changes and the triggering of earthquakes[J].Bulletin of the Seismological Society of America,78(3):935-953.
Li L,Chen Q F,Cheng X,et al.2007.Spatial clustering and repeating of seismic events observed along the 1976 Tangshan fault,north China[J].Geophysical Research Letters,34(23):229-241.https://doi.org/10.1029/2007GL031594.
Parsons T,Dreger D S.2000.Static-stress impact of the 1992 Landers earthquake sequence on nucleation and slip at the site of the 1999 M=7.1 Hector Mine earthquake,southern California[J].Geophysical Research Letters,27(13):1949-1952.
Rice J R,Cleary M P.1976.Some basic stress diffusion solutions for fluid-saturated elastic porous media with compressible constituents[J].Reviews of Geophysics,14(2):227-241.
Rice J R.1992.Fault stress states,pore pressure distributions,and the weakness of the San Andreas fault[C].International Geophysics Academic Press,51:475-503,doi:10.1016/S0074-6142(08)62835-1
Robinson R,Zhou S Y.2005.Stress Interactions within the Tangshan,China,Earthquake Sequence of 1976[J].Bulletin of the Seismological Society of America,95(6):2501-2505.
Shen Z,Zhao C,Yin A,et al.2000.Contemporary crustal deformation in east Asia constrained by Global Positioning System measurements[J].Journal of Geophysical Research:Solid Earth,105(B3):5721-5734.
Skempton A W.1954.The pore-pressure coefficients A and B[J].Geotechnique,4(4):143-147.
Stein S,Liu M.2009.Long aftershock sequences within continents and implications for earthquake hazard assessment[J].Nature,462:87-89.
Syed Tabrez A,Freed A M,Calais E,et al.2008.Coulomb stress evolution in Northeastern Caribbean over the past 250 years due to coseismic,postseismic and interseismic deformation[J].Geophysical Journal International,174(3):904-918.
Wan Y,Shen Z.2010.Static Coulomb stress changes on faults caused by the 2008 MW7.9 Wenchuan,China earthquake[J].Tectonophysics,491(1-4):105-118.
Wang R,Lorenzo-Martín F,Roth F.2006.PSGRN/PSCMP—a new code for calculating co-and post-seismic deformation,geoid and gravity changes based on the viscoelastic-gravitational dislocation theory[J].Computers & Geosciences,32(4):527-541.

备注

引言

1 模型建立

2 计算结果

3 讨论

4 结论

期刊信息