HUA Qian,
LIANG ChunTao,
YANG YiHai et al
.2020.Study on ambient seismic noise tomography of eastern Tibetan Plateau based on simulated annealing method Chinese Journal of Geophysics(in Chinese),63(5): 1787-1801,doi: 10.6038/cjg2020N0371
Study on ambient seismic noise tomography of eastern Tibetan Plateau based on simulated annealing method
HUA Qian1, LIANG ChunTao2,3, YANG YiHai1, LI ZhongQuan4, SU JinRong5
1. Shaanxi Earthquake Agency, Xi'an 710068, China; 2. Key Lab. of Earth Exploration and Information Technique of Ministry of Education(Chengdu University of Technology), Chengdu 610059, China; 3. State Key Lab. of Geohazard Prevention and Geoenvironment Protection(Chengdu University of Technology), Chengdu 610059, China; 4. Key Laboratory of Tectonic Controls on Mineralization and Hydrocarbon Accumulation, Ministry of Land and Resources(Chengdu University of Technology), Chengdu 610059, China; 5. Sichuan Earthquake Agency, Chengdu 610041, China
摘要 青藏高原是全球造山带研究的热点地区，此前在青藏高原开展的三维层析成像研究大多基于线性反演方法.本文利用青藏高原东缘及邻区布设的127个宽频带固定地震台站记录的连续波形资料，首先通过噪声互相关提取了3~50 s Rayleigh波群速度频散曲线并反演得到群速度分布，再进一步采用模拟退火法反演了研究区的三维S波速度及泊松比结构.结果显示：（1）松潘—甘孜地块的中下地壳低速异常主要分布在龙日坝断裂带、鲜水河断裂带、龙门山断裂带和岷山隆起所围限的区域，而该区域的中下地壳仅具有中等泊松比值，推测松潘—甘孜地块中下地壳的低速物质可能是青藏高原与扬子块体长期相互作用产生的塑性低速滑脱层；上地壳脆性物质在板块作用下沿中地壳低速滑脱层顶界面发生逆冲增厚，造成龙门山的持续抬升和地形起伏，并在构造边界带形成了应变积累和应力集中；而龙门山断裂带的上地壳低速软弱物质为地壳发生破裂提供了有利条件，从而在某种程度上促进了汶川地震和芦山地震的发生.（2）岷山隆起一带中下地壳的高泊松比异常呈"凸起"形态，结合前人研究发现的较高热流和岩石快速抬升现象，推测岷山隆起一带可能存在岩石圈的拆沉，导致地幔热物质上涌而形成下地壳高泊松比物质.（3）川滇地块的北部和南部具有不同的S波速度和泊松比分布特征.30 km深度下川滇地块北部具有明显的低速异常，而该深度下并不具有明显的高泊松比值特征；此外剖面成像结果也显示川滇地块内的低速异常与高泊松比的分布不一致，因此川滇地块的研究结果不支持下地壳流模型.综合其他地震学证据，本文认为川滇地块的变形模式为上地壳纯剪切增厚，块体变形主要受块体内部的走滑断裂及活动边界断裂控制.
Abstract：The Tibetan Plateau is a hotspot region in the study of global orogenic belts, previous studies on ambient seismic noise tomography in the Tibetan Plateau were mostly based on linear inversion. In this study, one-year continuous waveform data recorded by 127 broadband seismic stations in the eastern Tibet were collected. Firstly, the Rayleigh wave group velocity dispersion curves at periods 3~50 s were extracted by cross-correlation and then the group velocity distributions were inverted by tomography. Subsequently, the simulated annealing method was employed to invert the 3-D S-wave velocity and Poisson's ratio. Our results indicate:(1)The low-velocity anomaly in lower-to-middle crust of the Songpan-Garzê block is mainly confined by the Longriba fault, Xianshuihe fault, Longmenshan fault and Minshan uplift, however, this region just has medium Poisson's ratio at this depth, so it is speculated that the low-velocity materials in the middle-to-lower crust of the Songpan-Garzê block may be the plastic low-velocity detachment layer which produced by long-term interaction between the Tibetan Plateau and the Yangtze block, and the brittle upper crust thrusts and thickens along the top interface of the low-velocity detachment layer in the middle crust under the interaction of plates, causing the continuous uplift and topographic fluctuation of the Longmenshan as well as the strain accumulation and stress concentration in the tectonic boundaries. Meanwhile, the local low-velocity materials in the upper crust of the Longmenshan fault provide favorable condition for the rupture of crust, which promote the occurrence of Wenchuan and Lushan earthquakes to some extent.(2) The middle-to-lower crust of the Minshan uplift features as high Poisson's ratio, which presents a "bulge" shape. Combined with the phenomena of higher heat flow and rapid uplift of rocks founded by previous studies, the Minshan uplift may suffers the lithosphere delamination, resulting in the regional upwelling of hot mantle materials as well as forming the high Poisson's ratio structure in the lower crust.(3)The northern and southern Sichuan-Yunnan diamond blocks have different S-wave velocities and Poisson's ratio characteristics. At 30 km depth, low-velocity anomaly is significant in the northern Sichuan-Yunnan diamond block, while there is no obvious high Poisson's ratio structure at this depth. In addition, the profile imaging results also show that the distributions of low-velocity anomalies and high Poisson's ratio in the Sichuan-Yunnan diamond block are inconsistent, as a result, the lower crustal flow model cannot be supported with our results. Based on other seismological evidences, our study supports that the deformation model of Sichuan-Yunnan diamond block is pure shearing, the deformations of the block are mainly controlled by the strike-slip faults within the block and active boundary faults.
Bao X W, Sun X X, Xu M J, et al. 2015. Two crustal low-velocity channels beneath SE Tibet revealed by joint inversion of Rayleigh wave dispersion and receiver function. Earth and Planetary Science Letters, 415:16-24. Barmin M P, Ritzwoller M H, Levshin A. 2001. A fast and reliable method for surface wave tomography. Pure and Applied Geophysics, 158(8):1351-1375. Beaumont C, Jamieson R A, Nguyen M H, et al. 2001. Himalayan tectonics explained by extrusion of a low-viscosity crustal channel coupled to focused surface denudation. Nature, 414(6865):738-742. Bensen G B, Ritzwoller M H, Barmin M P, et al. 2007. Processing seismic ambient noise data to obtain reliable broad-band surface wave dispersion measurements. Geophysical Journal International, 169(3):1239-1260. Burchfiel B C, Royden L H, Van Der Hilst R D, et al. 2008. A geological and geophysical context for the Wenchuan earthquake of 12 May 2008, Sichuan, People's Republic of China. GSA Today, 18(7):4-11. Chen Y, Zhang Z J, Sun C Q, et al. 2013. Crustal anisotropy from Moho converted Ps wave splitting analysis and geodynamic implications beneath the eastern margin of Tibet and surrounding regions. Gondwana Research, 24(3-4):946-957. Clark M K, Royden L H. 2000. Topographic ooze:building the eastern margin of Tibet by lower crustal flow. Geology, 28(8):703-706. Clark M K, Bush J W M, Royden L H. 2005. Dynamic topography produced by lower crustal flow against rheological strength heterogeneities bordering the Tibetan Plateau. Geophysical Journal International, 162(2):575-590. Deng Q D, Chen S F, Zhao X L. 1994. Tectonics, scismisity and dynamics of Longmenshan Mountains and its adjacent regions. Seismology and Geology (in Chinese), 16(4):389-403. Deng Q D, Cheng S P, Ma J, et al. 2014. Seismic activities and earthquake potential in the Tibetan Planteau. Chinese Journal of Geophysics (in Chinese), 57(7):2025-2042, doi:10.6038/cjg20140701. Dziewonski A, Bloch S, Landisman M. 1969. A technique for the analysis of transient seismic signals. Bulletin of the Seismological Society of America, 59(1):427-444. Fan L P, Wu J P, Fang L H, et al. 2015. The characteristic of Rayleigh wave group velocities in the southeastern margin of the Tibetan Plateau and its tectonic implication. Chinese Journal of Geophysics (in Chinese), 58(5):1555-1567, doi:10.6038/cjg20150509. Herrmann R B. 1973. Some aspects of band-pass filtering of surface waves. Bulletin of the Seismological Society of America, 63(2):663-671. Herrmann R B, Ammon C J. 2004. Surface waves, receiver functions and crustal structure.//Computer Programs in Seismology, Version 3.30. Saint Louis:Saint Louis University. Houseman G, England P. 1993. Crustal thickening versus lateral expulsion in the Indian-Asian continental collision. Journal of Geophysical Research:Solid Earth, 98(B7):12233-12249. Hu J F, Su Y J, Zhu X G, et al. 2005. S-wave velocity and Passion's ratio structure of crust in Yunnan and its implication. Science in China Series D:Earth Sciences, 48(2):210-218. Hubbard J, Shaw J H. 2009. Uplift of the Longmen shan and Tibetan plateau, and the 2008 Wenchuan (M=7.9) earthquake. Nature, 458(7235):194-197. Ingber L. 1989. Very fast simulated re-annealing. Mathematical and Computer Modelling, 12(8):967-973, doi:10.1016/0895-7177(89)90202-1. Jiang G Z, Gao P, Rao S, et al. 2016. Compilation of heat flow data in the continental area of China (4th edition). Chinese Journal of Geophysics (in Chinese), 59(8):2892-2910, doi:10.6038/cjg20160815. Kirby E, Harkins N. 2013. Distributed deformation around the eastern tip of the Kunlun fault. International Journal of Earth Sciences, 102(7):1759-1772. Kirkpatrick S, Gelatt C D Jr, Vecchi M P. 1983. Optimization by simulated annealing. Science, 220(4598):671-680, doi:10.1126/science.220.4598.671. Lev E, Long D M, Van Der Hilst R D. 2006. Seismic anisotropy in Eastern Tibet from shear wave splitting reveals changes in lithospheric deformation. Earth and Planetary Science Letters, 251(3-4):293-304. Li H Y, Su W, Wang C Y, et al. 2009. Ambient noise Rayleigh wave tomography in western Sichuan and eastern Tibet. Earth and Planetary Science Letters, 282(1-4):201-211, doi:10.1016/j.epsl.2009.03.021. Liang C T, Langston C A. 2008. Ambient seismic noise tomography and structure of eastern North America. Journal of Geophysical Research:Solid Earth, 113(B3):B03309, doi:10.1029/2007JB005350. Liang C T, Langston C A. 2009. Three-dimensional crustal structure of eastern North America extracted from ambient noise. Journal of Geophysical Research:Solid Earth, 114(B3):B03310, doi:10.1029/2008JB005919. Liu Q Y, Van Der Hilst R D, Li Y, et al. 2014. Eastward expansion of the Tibetan Plateau by crustal flow and strain partitioning across faults. Nature Geoscience, 7(5):361-365. Liu Z, Tian X B, Gao R, et al. 2017. New images of the crustal structure beneath eastern Tibet from a high-density seismic array. Earth and Planetary Science Letters, 480:33-41. Luo J, Zhao C P, Lü J, et al. 2016. Characteristics of focal mechanisms and the stress field in the southeastern margin of the Tibetan Plateau. Pure and Applied Geophysics, 173(8):2687-2710. Panza G F. 1981. The resolving power of seismic surface waves with respect to crust and upper mantle structural models.//Cassinis R ed. The Solution of the Inverse Problem in Geophysical Interpretation. Boston, MA:Springer,39-77, doi:10.1007/978-1-4684-3962-5_3. Rothman D H. 1985. Nonlinear inversion, statistical mechanics, and residual statics estimation. Geophysics, 50(12):2784-2796. Roux P, Sabra K G, Kuperman W A, et al. 2005. Ambient noise cross-correlation in free space:theoretical approach. The Journal of the Acoustical Society of America, 117(1):79-84. Royden L H, Burchfiel B C, King R W, et al. 1997. Surface deformation and lower crustal flow in eastern Tibet. Science, 276(5313):788-790. Sen M K, Stoffa P L. 1991. Nonlinear one-dimensional seismic waveform inversion using simulated annealing. Geophysics, 56(10):1624-1638. Shapiro N M, Ritzwoller M H. 2002. Monte-Carlo inversion for a global shear-velocity model of the crust and upper mantle. Geophysical Journal International, 151(1):88-105, doi:10.1046/j.1365-246X.2002.01742.x. Shen Z K, Lü J N, Wang M, et al. 2005. Contemporary crustal deformation around the southeast borderland of the Tibetan Plateau. Journal of Geophysical Research:Solid Earth, 110(B11):B11409, doi:10.1029/2004JB003421. Tapponnier P, Peltzer G, Le Dain A Y, et al. 1982. Propagating extrusion tectonics in Asia:new insights from simple experiments with plasticine. Geology, 10(12):611-616. Wang C Y, Lou H, Lü Z Y, et al. 2008. S-wave crustal and upper mantle's velocity structure in the eastern Tibetan Plateau-Deep environment of lower crustal flow. Science in China Series D:Earth Sciences, 51(2):263-274. Wang S, Xu X Y, Hu J F. 2015. Review on the study of crustal structure and geodynamic models for the southeast margin of the Tibetan Plateau. Chinese Journal of Geophysics (in Chinese), 58(11):4235-4253, doi:10.6038/cjg20151129. Wang X, Chen L, Ai Y S, et al. 2018. Crustal structure and deformation beneath eastern and northeastern Tibet revealed by P-wave receiver functions. Earth and Planetary Science Letters, 497:69-79. Wang X C, Ding Z F, Wu Y, et al. 2017. Crustal thicknesses and Poisson's ratios beneath the northern section of the north-south seismic belt and surrounding areas in China. Chinese Journal of Geophysics (in Chinese), 60(6):2080-2090, doi:10.6038/cjg20170605. Wapenaar K. 2004. Retrieving the elastodynamic Green's function of an arbitrary inhomogeneous medium by cross correlation. Physical Review Letters, 93(25):254301. Weaver R L, Lobkis O I. 2001. Ultrasonics without a source:thermal fluctuation correlations at MHz frequencies. Physical Review Letters, 87(13):134301. Wessel P, Smith W H F. 1995. New version of the Generic Mapping Tools. Eos, 76(33):329. Xie J Y, Ritzwoller M H, Shen W S, et al. 2013. Crustal radial anisotropy across eastern Tibet and the western Yangtze craton. Journal of Geophysical Research:Solid Earth, 118(8):4226-4252. Xu L L, Rondenay S, Van Der Hilst R D. 2007. Structure of the crust beneath the southeastern Tibetan Plateau from teleseismic receiver functions. Physics of the Earth and Planetary Interiors, 165(3-4):176-193, doi:10.1016/j.pepi.2007.09.002. Xu X W, Wen X Z, Zheng R Z, et al. 2003. Pattern of latest tectonic motion and its dynamics for active blocks in Sichuan-Yunnan region, China. Science in China Series D:Earth Sciences, 46(2):210-226. Xu X W, Wen X Z, Yu G H, et al. 2005. Average slip rate, earthquake rupturing segmentation and recurrence behavior on the Litang fault zone, western Sichuan Province, China. Science in China Series D:Earth Sciences, 48(8):1183-1196. Xu X W, Wen X Z, Chen G H, et al. 2008. Discovery of the Longriba fault zone in eastern Bayan Har block, China and its tectonic implication. Science in China Series D:Earth Sciences, 51(9):1209-1223, doi:10.1007/s11430-008-0097-1. Xu Z Q, Jiang M, Yang J S, et al. 1999. Mantle diapir and inward intracontinental subduction:A discussion on the mechanism of uplift of the Qinghai-Tibet Plateau. Geological Society of America Special Papers, 328:19-31. Xu Z Q, Ji S C, Li H B, et al. 2008. Uplift of the Longmen Shan range and the Wenchuan earthquake. Episodes, 31(3):291-301. Yang Y H, Liang C T, Su J R. 2015. Focal mechanism inversion based on regional model inverted from receiver function and its application to the Lushan earthquake sequence. Chinese Journal of Geophysics (in Chinese), 58(10):3583-3600, doi:10.6038/cjg20151013. Yang Y H, Fan J, Hua Q, et al. 2017. Inversion for the focal mechanisms of the 2017 Jiuzhaigou M7.0 earthquake sequence using near-field full waveforms. Chinese Journal of Geophysics (in Chinese), 60(10):4098-4101, doi:10.6038/cjg20171034. Yang Y H, Liang C T, Fang L H, et al. 2018. A comprehensive analysis on the stress field and seismic anisotropy in Eastern Tibet. Tectonics, 37(6):1648-1657. Yang Y J, Ritzwoller M H, Zheng Y, et al. 2012. A synoptic view of the distribution and connectivity of the mid-crustal low velocity zone beneath Tibet. Journal of Geophysical Research:Solid Earth, 117(B4):B04303, doi:10.1029/2011JB008810. Yao H J, van Der Hilst R D, De Hoop M V. 2006. Surface-wave array tomography in SE Tibet from ambient seismic noise and two-station analysis-I. Phase velocity maps. Geophysical Journal International, 166(2):732-744. Yao H J, Beghein C, Van Der Hilst R D. 2008. Surface wave array tomography in SE Tibet from ambient seismic noise and two-station analysis-Ⅱ. Crustal and upper-mantle. Geophysical Journal International, 173(1):205-219. Yao H J, Van Der Hilst R D, Montagner J P. 2010. Heterogeneity and anisotropy of the lithosphere of SE Tibet from surface wave array tomography. Journal of Geophysical Research, 115(B12):B12307, doi:10.1029/2009JB007142. Yao Y. 1995. Improvement on nonlinear geophysical inversion simulated annealing. Acta Geophysica Sinica (in Chinese), 38(5):643-650. Yi G X, Long F, Zhang Z W. 2012. Spatial and temporal variation of focal mechanisms for aftershocks of the 2008 MS8.0 Wenchuan earthquake. Chinese Journal of Geophysics (in Chinese), 55(4):1213-1227, doi:10.6038/j.issn.0001-5733.2012.04.017. Yi G X, Long F, Vallage A, et al. 2016. Focal mechanism and tectonic deformation in the seismogenic area of the 2013 Lushan earthquake sequence, southwestern China. Chinese Journal of Geophysics (in Chinese), 59(10):3711-3731, doi:10.6038/cjg20161017. Yi G X, Long F, Liang M J, et al. 2017a. Focal mechanism solutions and seismogenic structure of the 8 August 2017 M7.0 Jiuzhaigou earthquake and its aftershocks, northern Sichuan. Chinese Journal of Geophysics (in Chinese), 60(10):4083-4097, doi:10.6038/cjg20171033. Yi G X, Long F, Liang M J, et al. 2017b. Seismogenic structure of the M4.9 and M5.1 Litang earthquakes on 23 September 2016 in southwestern China. Seismology and Geology (in Chinese), 39(5):949-963. Yin A, Harrison T M. 2000. Geologic evolution of the Himalayan-Tibetan orogen. Annual Review of Earth and Planetary Sciences, 28:211-280. Zelt C A. 1998. Lateral velocity resolution from three-D seismic refraction data. Geophysical Journal International, 135(3):1101-1112. Zhang X M, Teng J W, Sun R M, et al. 2014. Structural model of the lithosphere-asthenosphere system beneath the Qinghai-Tibet Plateau and its adjacent areas. Tectonophysics, 634:208-226, doi:10.1016/j.tecto.2014.08017. Zhao L F, Xie X B, He J K, et al. 2013. Crustal flow pattern beneath the Tibetan Plateau constrained by regional Lg-wave Q tomography. Earth and Planetary Science Letters, 383:113-122. Zheng C, Ding Z F, Song X D. 2016. Joint inversion of surface wave dispersion and receiver functions for crustal and uppermost mantle structure in Southeast Tibetan Plateau. Chinese Journal of Geophysics (in Chinese), 59(9):3223-3236, doi:10.6038/cjg20160908. Zhu J S. 2008. The Wenchuan earthquake occurrence background in deep structure and dynamics of lithosphere. Journal of Chengdu University of Technology (Science & Technology Edition) (in Chinese), 35(4):348-356, doi:10.3969/j.issn.1671-9727.2008.04.002. Zhu J S, Zhao J M, Jiang X T, et al. 2012. Crustal flow beneath the eastern margin of the Tibetan plateau. Earthquake Science, 25(5-6):469-483. Zhu J S, Wang X B, Yang Y H, et al. 2017. The crustal flow beneath the eastern margin of the Tibetan Plateau and its process of dynamic. Chinese Journal of Geophysics (in Chinese), 60(6):2038-2057, doi:10.6038/cjg20170602. 附中文参考文献 邓起东, 陈社发, 赵小麟. 1994. 龙门山及其邻区的构造和地震活动及动力学. 地震地质, 16(4):389-403. 邓起东, 程绍平, 马冀等. 2014. 青藏高原地震活动特征及当前地震活动形势. 地球物理学报, 57(7):2025-2042, doi:10.6038/cjg20140701. 范莉苹, 吴建平, 房立华等. 2015. 青藏高原东南缘瑞利波群速度分布特征及其构造意义探讨. 地球物理学报, 58(5):1555-1567, doi:10.6038/cjg20150509. 姜光政,高鹏,饶松等. 2016. 中国大陆地区大地热流数据汇编(第四版). 地球物理学报, 59(8):2892-2910, doi:10.6038/cjg20160815. 胡家富, 苏有锦, 朱雄关等. 2003. 云南的地壳S波速度与泊松比结构及其意义. 中国科学(D辑), 33(8):714-722. 王椿镛, 楼海, 吕智勇等. 2008. 青藏高原东部地壳上地幔S波速度结构——下地壳流的深部环境. 中国科学 D辑:地球科学, 38(1):22-32. 王苏, 徐晓雅, 胡家富. 2015. 青藏高原东南缘的地壳结构与动力学模式研究综述. 地球物理学报, 58(11):4235-4253, doi:10.6038/cjg20151129. 王兴臣, 丁志峰, 武岩等. 2017. 中国南北地震带北段及其周缘地壳厚度与泊松比研究. 地球物理学报, 60(6):2080-2090, doi:10.6038/cjg20170605. 徐锡伟, 闻学泽, 郑荣章等. 2003. 川滇地区活动块体最新构造变动样式及其动力来源. 中国科学(D辑), 33(S1):151-162. 徐锡伟, 闻学泽, 于贵华等. 2005. 川西理塘断裂带平均滑动速率、地震破裂分段与复发特征. 中国科学 D辑:地球科学, 35(6):540-551. 徐锡伟, 闻学泽, 陈桂华等. 2008. 巴颜喀拉地块东部龙日坝断裂带的发现及其大地构造意义. 中国科学 D辑:地球科学, 38(5):529-542. 杨宜海, 梁春涛, 苏金蓉. 2015. 用接收函数建立区域模型的震源机制反演及其在芦山地震序列研究中的应用. 地球物理学报, 58(10):3583-3600, doi:10.6038/cjg20151013. 杨宜海, 范军, 花茜等. 2017. 近震全波形反演2017年九寨沟M7.0地震序列震源机制解. 地球物理学报, 60(10):4098-4104, doi:10.6038/cjg20171034. 姚姚. 1995. 地球物理非线性反演模拟退火法的改进. 地球物理学报, 38(5):643-650. 易桂喜, 龙锋, 张致伟. 2012. 汶川MS8.0地震余震震源机制时空分布特征. 地球物理学报, 55(4):1213-1227, doi:10.6038/j.issn.0001-5733.2012.04.017. 易桂喜, 龙锋, Vallage A等. 2016. 2013年芦山地震序列震源机制与震源区构造变形特征分析. 地球物理学报, 59(10):3711-3731, doi:10.6038/cjg20161017. 易桂喜, 龙锋, 梁明剑等. 2017a. 2017年8月8日九寨沟M7.0地震及余震震源机制解与发震构造分析. 地球物理学报, 60(10):4083-4097, doi:10.6038/cjg20171033. 易桂喜, 龙锋, 梁明剑等. 2017b. 2016年9月23日四川理塘M4.9和M5.1地震发震构造分析. 地震地质, 39(5):949-963. 张培震. 2008. 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. 中国科学 D辑:地球科学, 38(9):1041-1056. 郑晨, 丁志峰, 宋晓东. 2016. 利用面波频散与接收函数联合反演青藏高原东南缘地壳上地幔速度结构. 地球物理学报, 59(9):3223-3236, doi:10.6038/cjg20160908. 朱介寿. 2008. 汶川地震的岩石圈深部结构与动力学背景. 成都理工大学学报(自然科学版), 35(4):348-356, doi:10.3969/j.issn.1671-9727.2008.04.002. 朱介寿, 王绪本, 杨宜海等. 2017. 青藏高原东缘的地壳流及动力过程. 地球物理学报, 60(6):2038-2057, doi:10.6038/cjg20170602.
| 
