青藏高原东南部地震b值时空演化及其对区域应力场特征的启示

高雅婧; 罗纲; 王少坡; 周元泽

doi:10.7523/j.ucas.2021.0037

中国科学院大学学报 >

2022 , Vol. 39 >Issue 5: 627 - 638

DOI: https://doi.org/10.7523/j.ucas.2021.0037

地球科学

青藏高原东南部地震b值时空演化及其对区域应力场特征的启示

高雅婧 ,
罗纲 ,
王少坡 ,
周元泽

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1. 中国科学院大学地球与行星科学学院中国科学院计算地球动力学重点实验室, 北京 100049;
2. 武汉大学测绘学院, 武汉 430079;
3. 武汉大学地球空间环境与大地测量教育部重点实验室, 武汉 430079;
4. 陕西省自然资源厅, 西安 710082

收稿日期: 2020-12-23

修回日期: 2021-04-07

网络出版日期: 2021-04-07

基金资助

中国地震科学实验场专项（2019CSES0112）、国家自然科学基金（41974107，41574085）和地震数值预测联合实验室开放基金（2020LNEF01）资助

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The b-value spatiotemporal evolution in southeastern Tibetan Plateau and its implications on regional stress field characteristics

GAO Yajing ,
LUO Gang ,
WANG Shaopo ,
ZHOU Yuanze

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1. CAS Key Laboratory of Computational Geodynamics, College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;
2. School of Geodesy and Geomatics, Wuhan University, Wuhan 430079;
3. Key Laboratory of Geospace Environment and Geodesy of Ministry of Education, Wuhan University, Wuhan 430079, China;
4. Department of Natural Resources of Shaanxi Province, Xi'an 710082, China

Received date: 2020-12-23

Revised date: 2021-04-07

Online published: 2021-04-07

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摘要

区域应力分布特征是地震危险性评价的重要指标之一。采用青藏高原东南部1970—2019年的地震目录数据，使用最大似然法对该区进行地震b值时空扫描，得到该区b值时空分布特征；利用地震b值与应力的负相关关系，分析青藏高原东南部主要断裂带上的应力分布及变化。研究结果显示：1）在鲜水河—小江断裂系统的中部，大凉山断裂带附近区域的b值比安宁河—则木河断裂带附近区域低，推测大凉山断裂带承担较多的应力，可能是未来地震风险较高的断裂带；2）研究区浅层（0~20 km）比深层（20~40 km）的b值高，这是与浅层区域围压低、岩石倾向脆性破裂，而深层区域围压高、岩石倾向韧性变形的特征相一致的；3）汶川地震发生前后，震源及周边区域的b值经历了降低—升高—降低的过程，揭示了区域内应力的累积—释放—累积过程；地震震级越大，震前b值降低趋势持续越久，该地震的发生对b值的影响范围越大、b值波动越明显，距震中越近的区域的b值在地震前后的波动越明显；4）龙门山断裂带及其附近地区b值较低，推测该区域应力较大。

关键词： 地震b值; 震级-频度关系; 青藏高原东南部; 应力场; 龙门山断裂带

本文引用格式

高雅婧 , 罗纲 , 王少坡 , 周元泽 . 青藏高原东南部地震b值时空演化及其对区域应力场特征的启示[J]. 中国科学院大学学报, 2022 , 39(5) : 627 -638 . DOI: 10.7523/j.ucas.2021.0037

Abstract

Stress field is an important factor to assess regional seismic risk. We collected the seismic catalogue data from 1970 to 2019 in southeastern Tibetan Plateau, used the maximum likelihood method to calculate regional b values, and then obtained the spatial and temporal distribution of b values of this region. Based on the negative correlation between seismic b value and stress, we analyzed the stress distribution and variation on the major fault zones in southeastern Tibetan Plateau. The results are as follows. 1) In the center of Xianshuihe-Xiaojiang fault system, the b value of Daliangshan fault zone is lower than that of Anninghe-Zemuhe fault zone. This indicates that the stress on Daliangshan fault zone is greater and its seismic risk is relatively high in the future. 2) The b values in shallow layer (0-20 km) are higher than those of deep layer (20-40 km), which is consistent with the characteristics that confining pressure is low and rock tends to brittle fracture in the shallow, while confining pressure is high and rock tends to ductile deformation in the deep. 3) Before and after the 2008 Wenchuan earthquake, b value of epicenter area had a decrease-rise-decrease process, and this showed the accumulation-release-accumulation process of regional stress. The larger the magnitude of earthquake, the longer the decreasing trend of b value before the earthquake, the greater the impact of earthquake on b value. The closer to the epicenter, the greater the decrease of b value. 4) The b value of Longmenshan fault zone is relatively low at present and this shows that Longmenshan fault zone is accumulating stress.

Key words： b value; magnitude-frequency; southeastern Tibetan Plateau; stress field; Longmenshan fault zone

参考文献

[1] Jiang G Y, Xu C J, Wen Y M, et al. Contemporary tectonic stressing rates of major strike-slip faults in the Tibetan Plateau from GPS observations using Least-Squares Collocation[J]. Tectonophysics, 2014, 615/616:85-95.DOI:10.1016/j.tecto.2013.12.022.
[2] Gutenberg B, Richter C F. Frequency of earthquakes in California[J]. Bulletin of the Seismological Society of America, 1944, 34(4):185-188.DOI:10.1785/bssa0340040185.
[3] Main I G, Meredith P G, Sammonds P R. Temporal variations in seismic event rate and b-values from stress corrosion constitutive laws[J]. Tectonophysics, 1992, 211(1-4):233-246.DOI:10.1016/0040-1951(92)90061-a.
[4] Scholz C H. On the stress dependence of the earthquake b value[J]. Geophysical Research Letters, 2015, 42(5):1399-1402.DOI:10.1002/2014g1062863.
[5] Schorlemmer D, Wiemer S, Wyss M, et al. Earthquake statistics at Parkfield:2. Probabilistic forecasting and testing[J]. Journal of Geophysical Research:Solid Earth, 2004, 109(B12):B12308.DOI:10.1029/2004JB003235.
[6] Schorlemmer D, Wiemer S, Wyss M. Variations in earthquake-size distribution across different stress regimes[J]. Nature, 2005, 437(7058):539-542.DOI:10.1038/mature04094.
[7] 刘雁冰, 裴顺平. 汶川地震前后b值的时空变化及构造意义[J]. 地球物理学报, 2017, 60(6):2104-2112.DOI:10.6038/cjg20170607.
[8] Smith W D. The b-value as an earthquake precursor[J]. Nature, 1981, 289(5794):136-139.DOI:10.1038/289136a0.
[9] Robinson R. Variation of energy release, rate of occurrence and b-value of earthquakes in the Main Seismic Region, New Zealand[J]. Physics of the Earth and Planetary Interiors, 1979, 18(3):209-220.
[10] 刘艳辉, 赵根模, 吴中海, 等. 青藏高原东南缘及邻区近年来地震b值特征[J]. 地质通报, 2015, 34(1):58-70.DOI:10.3969/j.issn.1671-2552.2005.01.005.
[11] 史海霞, 孟令媛, 张雪梅, 等. 汶川地震前的b值变化[J]. 地球物理学报, 2018, 61(5):1874-1882.DOI:10.6038/cjg2018M0024.
[12] 钱晓东, 秦嘉政. 小江断裂带及周边地区强震危险性分析[J]. 地震研究, 2008, 31(4):354-361.DOI:10.3969/j.issn.1000-0666.2008.04.010.
[13] 易桂喜, 闻学泽, 苏有锦. 川滇活动地块东边界强震危险性研究[J]. 地球物理学报, 2008, 51(6):1719-1725.DOI:10.3321/j.issn:0001-5733.2008.06.012.
[14] 刘静伟, 吕悦军, 谢富仁. 利用b值空间分布解析2014年11月22日康定M_S 6.3地震的发生[J]. 地球物理学进展, 2016, 31(2):553-558.DOI:10.6038/pg20160207.
[15] 朱艾斓, 徐锡伟, 甘卫军, 等. 鲜水河-安宁河-则木河断裂带上可能存在的凹凸体:来自背景地震活动性的证据[J]. 地学前缘, 2009, 16(1):217-225.DOI:10.3321/j.issn:1005-2321.2009.01.024.
[16] Shen Z K, Lü J, Wang M, et al. Contemporary crustal deformation around the southeast borderland of the Tibetan Plateau[J]. Journal of Geophysical Research:Solid Earth, 2005, 110(B11):1-17.DOI:10.1029/2004jb003421.
[17] Royden L H, Burchfiel B C, King R W, et al. Surface deformation and lower crustal flow in eastern Tibet[J]. Science, 1997, 276(5313):788-790.DOI:10.1126/science.276.5313.788.
[18] 程佳, 徐锡伟, 甘卫军, 等. 青藏高原东南缘地震活动与地壳运动所反映的块体特征及其动力来源[J]. 地球物理学报, 2012, 55(4):1198-1212.DOI:10.6038/j.issn.0001-5733.2012.04.016.
[19] 徐锡伟, 张培震, 闻学泽, 等. 川西及其邻近地区活动构造基本特征与强震复发模型[J]. 地震地质, 2005, 27(3):446-461.DOI:10.3969/j.issn.0253-4967.2005.03.010.
[20] Wen X Z, Ma S L, Xu X W, et al. Historical pattern and behavior of earthquake ruptures along the eastern boundary of the Sichuan-Yunnan faulted-block, southwestern China[J]. Physics of the Earth and Planetary Interiors, 2008, 168(1/2):16-36.DOI:10.1016/j.pepi.2008.04.013.
[21] 张培震. 青藏高原东缘川西地区的现今构造变形、应变分配与深部动力过程[J]. 中国科学(D辑:地球科学), 2008, 38(9):1041-1056.
[22] 何宏林, 魏占玉, 陈长云, 等. 2008年汶川地震破裂的滑移向量[J]. 地学前缘, 2010, 17(5):19-32.
[23] 徐锡伟, 陈桂华, 于贵华, 等. 5·12汶川地震地表破裂基本参数的再论证及其构造内涵分析[J]. 地球物理学报, 2010, 53(10):2321-2336.DOI:10.3969/j.issn.0001-5733.2010.10.006.
[24] Aki K. Maximum likelihood estimation of b in the formula log₁₀N=a-bM and its confidence limits[J]. Bulletin of the Earthquake Research Institute, University of Tokyo, 1965, 43(2):237-239.
[25] Utsu T. A statistical significance test of the difference in b-value between two earthquake groups[J]. Journal of Physics of the Earth, 1966, 14(2):37-40.DOI:10.4294/jpe1952.14.37.
[26] 李莹甄, 殷娜, 李小晗. 不同震级标度转换关系研究概述[J]. 地震工程学报, 2014, 36(1):80-87.DOI:10.3969/j.issn.1000-0844.2014.01.0080.
[27] 马宏生, 张国民, 周龙泉, 等. 川滇地区中小震重新定位与速度结构的联合反演研究[J]. 地震, 2008, 28(2):29-38.DOI:10.3969/j.issn.1000-3274.2008.02.003.
[28] 朱艾斓, 徐锡伟, 周永胜, 等. 川西地区小震重新定位及其活动构造意义[J]. 地球物理学报, 2005, 48(3):629-636.DOI:10.3321/j.issn:0001-5733.2005.03.021.
[29] 王椿镛, 韩渭宾, 吴建平, 等. 松潘-甘孜造山带地壳速度结构[J]. 地震学报, 2003, 25(3):229-241.DOI:10.3321/j.issn:0253-3782.2003.03.001.
[30] Amitrano D. Brittle-ductile transition and associated seismicity:experimental and numerical studies and relationship with the b value[J]. Journal of Geophysical Research:Solid Earth, 2003, 108(B1):2044.DOI:10.1029/2001JB000680.
[31] 马鸿庆. 大、中地震前b值的区域分布[J]. 地球物理学报, 1982, 25(2):163-171.
[32] 周翠英, 魏光兴, 赵兴兰. 山东中、强地震前近场与远场地震活动性异常的某些差异[J]. 地震研究, 1987, 10(1):1-9.
[33] Habermann R E. Precursory seismic quiescence:past, present, and future[J]. Pure and Applied Geophysics, 1988, 126(2-4):279-318.DOI:10.1007/BF00879000.
[34] Huang Q H, Sobolev G A, Nagao T. Characteristics of the seismic quiescence and activation patterns before the M=7.2 Kobe earthquake, January 17, 1995[J]. Tectonophysics, 2001, 337(1/2):99-116.DOI:10.1016/S0040-1951(01)00073-7.
[35] Huang Q H. Search for reliable precursors:a case study of the seismic quiescence of the 2000 western Tottori prefecture earthquake[J]. Journal of Geophysical Research:Solid Earth, 2006, 111(B4):B04301.DOI:10.1029/2005JB003982.
[36] Huang Q H. Seismicity changes prior to the M_S 8.0 Wenchuan earthquake in Sichuan, China[J]. Geophysical Research Letters, 2008, 35(23):L23308.DOI:10.1029/2008GL036270.
[37] Huang Q H. Seismicity pattern changes prior to large earthquakes:an approach of the RTL algorithm[J]. Terrestrial, Atmospheric and Oceanic Sciences, 2004, 15(3):469-491.DOI:10.3319/tao.2004.15.3.469(ep).
[38] Huang Q H, Nagao T. Seismic quiescence before the 2000M=7.3 Tottori earthquake[J]. Geophysical Research Letters, 2002, 29(12):1578.DOI:10.1029/2001g1013835.
[39] 陈学忠, 李艳娥. 2010年4月14日青海玉树7.1级地震前震中附近地区小震活动的周、月频次分布特征[J]. 中国地震, 2012, 28(1):10-21.DOI:10.3969/j.issn.1001-4683.2012.01.002.
[40] Burchfiel B C, Chen Z L, Yupinc L, et al. Tectonics of the Longmen Shan and adjacent regions, central China[J]. International Geology Review, 1995, 37(8):661-735.DOI:10.1080/00206819509465424.
[41] Burchfiel B C, Royden L H, van der Hilst R D, et al. A geological and geophysical context for the Wenchuan earthquake of 12 May 2008, Sichuan, People's Republic of China[J]. GSA Today, 2008, 18(7):4-11.DOI:10.1130/gsatg18a.1.
[42] 卢华复, 贾东, 王良书, 等. 关于汶川地震发震机制[J]. 高校地质学报, 2008, 14(2):133-138.DOI:10.3969/j.issn.1006-7493.2008.02.001.
[43] 李智武, 刘树根, 陈洪德, 等. 龙门山冲断带分段-分带性构造格局及其差异变形特征[J]. 成都理工大学学报(自然科学版), 2008, 35(4):440-454.DOI:10.3969/j.issn.1671-9727.2008.04.014.
[44] 徐锡伟, 于贵华, 马文涛, 等. 中国大陆中轴构造带地壳最新构造变动样式及其动力学内涵[J]. 地学前缘, 2003, 10(S1):160-167.
[45] 徐锡伟, 闻学泽, 叶建青, 等. 汶川M_S 8.0地震地表破裂带及其发震构造[J]. 地震地质, 2008, 30(3):597-629.DOI:10.3969/j.issn.0253-4967.2008.03.003.
[46] 邓起东, 陈社发, 赵小麟. 龙门山及其邻区的构造和地震活动及动力学[J]. 地震地质, 1994, 16(4):389-403.
[47] 魏占玉, 何宏林, 石峰, 等. 大凉山断裂带南段滑动速率估计[J]. 地震地质, 2012, 34(2):282-293.DOI:10.3969/j.issn.0253-4967.2012.02.007.
[48] 何宏林, 池田安隆, 何玉林, 等. 新生的大凉山断裂带:鲜水河-小江断裂系中段的裁弯取直[J]. 中国科学(D辑:地球科学), 2008, 38(5):564-574.
[49] Scholz C H. The frequency-magnitude relation of microfracturing in rock and its relation to earthquakes[J]. Bulletin of the Seismological Society of America, 1968, 58(1):399-415.DOI:10.1785/bssa0580010399.
[50] Byerlee J D. Brittle-ductile transition in rocks[J]. Journal of Geophysical Research Atmospheres, 1968, 73(14):4741-4750.DOI:10.1029/jb073i014p04741.
[51] Tormann T, Enescu B, Woessner J, et al. Randomness of megathrust earthquakes implied by rapid stress recovery after the Japan earthquake[J]. Nature Geoscience, 2015, 8(2):152-158.DOI:10.1038/ngeo2343.
[52] Nanjo K Z, Hirata N, Obara K, et al. Decade-scale decrease in b value prior to the M9-class 2011 Tohoku and 2004 Sumatra quakes[J]. Geophysical Research Letters, 2012, 39(20):L20304.DOI:10.1029/2012GL052997.
[53] Chan C H, Wu Y M, Tseng T L, et al. Spatial and temporal evolution of b-values before large earthquakes in Taiwan[J]. Tectonophysics, 2012, 532-535:215-222.
[54] Nakaya S. Spatiotemporal variation in b value within the subducting slab prior to the 2003 Tokachi-Oki earthquake (M 8.0), Japan[J]. Journal of Geophysical Research:Solid Earth, 2006, 111(B3):B03311.DOI:10.1029/2005JB003658.
[55] Narteau C, Byrdina S, Shebalin P, et al. Common dependence on stress for the two fundamental laws of statistical seismology[J]. Nature, 2009, 462(7273):642-645.DOI:10.1038/nature08553.
[56] 韩渭宾, 蒋国芳. 川滇地区强震活动分布特征及其与地壳块体构造背景关系的研究[J]. 地震学报, 2004, 26(2):211-222.DOI:10.3321/j.issn:0253-3782.2004.02.011.
[57] 韩渭宾, 蒋国芳. 大凉山断裂带与安宁河-则木河断裂带的地震活动性分析[J]. 地震研究, 2005, 28(3):207-212.DOI:10.3969/j.issn.1000-0666.2005.03.001.
[58] 易桂喜, 闻学泽, 王思维, 等. 由地震活动参数分析龙门山-岷山断裂带的现今活动习性与强震危险性[J]. 中国地震, 2006, 22(2):117-125.DOI:10.3969/j.issn.1001-4683.2006.02.001.
[59] 易桂喜, 范军, 闻学泽. 由现今地震活动分析鲜水河断裂带中-南段活动习性与强震危险地段[J]. 地震, 2005, 25(1):58-66.DOI:10.3969/j.issn.1000-3274.2005.01.008.

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