HUANG ChenYu,
CHANG LiJun,
DING ZhiFeng
.2021.Crustal anisotropy in the eastern Himalayan syntaxis and adjacent areas Chinese Journal of Geophysics(in Chinese),64(11): 3970-3982,doi: 10.6038/cjg2021P0034
喜马拉雅东构造结及周边地区地壳各向异性特征
黄臣宇, 常利军, 丁志峰
中国地震局地球物理研究所, 北京 100081
Crustal anisotropy in the eastern Himalayan syntaxis and adjacent areas
HUANG ChenYu, CHANG LiJun, DING ZhiFeng
Institute of Geophysics, China Earthquake Administration, Beijing 100081, China
Abstract:This work is based on teleseismic waveform data of 48 broadband seismic stations in the eastern Himalayan syntaxis and adjacent areas. We acquired 295 pairs of anisotropy parameters by measurement to Pms wave splitting, which permit to image the crustal anisotropy of the study area. Results show that the fast wave polarization directions of the eastern Himalayan syntaxis are NE-SW, rotating clockwise in the adjacent areas. The delay time of the Pms wave splitting in the study area ranges from 0.11 s to 0.30 s, with an average of 0.24 s. Comparison of the Pms wave splitting, the direct S wave splitting and the teleseismic SKS wave splitting suggests that the crustal anisotropy of the eastern Himalayan syntaxis and adjacent areas is mainly from the middle and lower crust, and the Pms wave splitting mainly reflects the anisotropy of the middle and lower crust. It also shows that the crust anisotropy has little effect on the SKS wave splitting, and SKS wave splitting is attributed to the anisotropy of the upper mantle. The fast wave polarization directions of the Pms wave splitting are well consistent with those of the direct S wave splitting and the teleseismic SKS wave splitting, and have good correlations with surface structures and deformation characteristics, indicating that the lithospheric deformation of the eastern Himalayan syntaxis and adjacent areas can be characterized by a vertical coherent deformation model.
Anderson D L. 1961. Elastic wave propagation in layered anisotropic media. Journal of Geophysical Research, 66(9):2953-2963. Barruol G, Mainprice D. 1993. A quantitative evaluation of the contribution of crustal rocks to the shear-wave splitting of teleseismic SKS waves. Physics of the Earth & Planetary Interiors, 78(3-4):281-300. Chang L J, Wang C Y, Ding Z F, et al.2008. Seismic anisotropy of upper mantle in the northeastern margin of the Tibetan Plateau. Chinese Journal of Geophysics (in Chinese), 51(2):431-438. Chang L J, Ding Z F, Wang C Y. 2010. Variations of shear wave splitting in the 2010 Yushu MS7.1 earthquake region. Chinese Journal of Geophysics (in Chinese), 53(11):2613-2619, doi:10.3969/j.issn.0001-5733.2010.11.009. Chang L J, Flesch L M, Wang C Y, et al. 2015. Vertical coherence of deformation in lithosphere in the eastern Himalayan syntaxis using GPS, Quaternary fault slip rates, and shear wave splitting data. Geophysical Research Letters, 42(14):5813-5819. Chang L J, Ding Z F, Wang C Y, et al. 2017. Vertical coherence of deformation in lithosphere in the NE margin of the Tibetan plateau using GPS and shear-wave splitting data. Tectonophysics, 699:93-101. Chang L J, Ding Z F, Wang C Y. 2018. Upper crustal anisotropy observed around the Longmenshan fault in the 2013 MS7.0 Lushan earthquake region. Earthquake Science, 31(4):187-198. 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. Cheng C, Bai L, Ding L, et al. 2017. Crustal structure of Eastern Himalayan Syntaxis revealed by receiver function method. Chinese Journal of Geophysics (in Chinese), 60(8):2969-2979, doi:10.6038/cjg20170806. Christensen N I. 1984. The magnitude, symmetry and origin of upper mantle anisotropy based on fabric analyses of ultramafic tectonites. Geophysical Journal International, 76(1):89-111. Crampin S. 1981. A review of wave motion in anisotropic and cracked elastic-media. Wave Motion, 3(4):343-391. Crampin S. 1984. Effective anisotropic elastic constants for wave propagation through cracked solids. Geophysical Journal International, 76(1):135-145. Crampin S, Atkinson B K. 1985. Microcracks in the Earth's crust. First Break, 3(3):16-20. Crampin S. 1994. The fracture criticality of crustal rocks. Geophysical Journal International, 118(2):428-438. Crampin S, Peacock S. 2008. A review of the current understanding of seismic shear-wave splitting in the Earth's crust and common fallacies in interpretation. Wave Motion, 45(6):675-722. Ding Z F,Zeng R S. 1996. Observation and study of shear wave anisotropy in Tibetan Plateau. Acta Geophysica Sinica (in Chinese), 39(2):211-220. Ding Z F, Wu Y, Wang H, et al. 2008. Variations of shear wave splitting in the 2008 Wenchuan earthquake region. Science in China Series D:Earth Sciences, 51(12):1712-1716. Gan W J, Zhang P Z, Shen Z K, et al. 2007. Present-day crustal motion within the Tibetan Plateau inferred from GPS measurements. Journal of Geophysical Research:Solid Earth, 112(B8):B08416, doi:10.1029/2005JB004120. Gao Y, Shi Y T, Chen A G. 2018. Crustal seismic anisotropy and compressive stress in the eastern margin of the Tibetan Plateau and the influence of the MS8.0 Wenchuan earthquake. Chinese Science Bulletin (in Chinese), 63(19):1934-1948. Gao Y, Chen A G, Shi Y T, et al. 2019. Preliminary analysis of crustal shear-wave splitting in the Sanjiang lateral collision zone of the southeast margin of the Tibetan Plateau and its tectonic implications. Geophysical Prospecting, 67(9):2432-2449. Guo T L, Gao Y. 2020. Seismic anisotropy in the upper crust within Tibetan Plateau revealed by shear-wave splitting. Chinese Journal of Geophysics (in Chinese), 63(3):1085-1103, doi:10.6038/cjg2020N0156. Jiang M, Lü Q T, Shi D N, et al. 1996. The study on the structure of crust and upper mantle with natural earthquakes in central Tibetan Plateau. Acta Geophysica Sinica (in Chinese), 39(4):438-439. Li G H, Bai L, Ding L, et al. 2020. Source parameters of the 2019 MS6.3 Medog earthquake and its tectonic implications. Chinese Journal of Geophysics (in Chinese), 63(3):1214-1223, doi:10.6038/cjg2020N0231. Ligorría J P, Ammon C J. 1999. Iterative deconvolution and receiver-function estimation. Bulletin of the Seismological Society of America, 89(5):1395-1400. Lü Q T, Ma K Y, Jiang M, et al. 1996. Seismic anisotropy beneath Southern Tibet. Acta Seismologica Sinica (in Chinese), 18(2):215-223. Nicolas A, Boudier F, Boullier A M. 1973. Mechanisms of flow in naturally and experimentally deformed peridotites. American Journal of Science, 273(10):853-876. Peng M, Tan H D, Jiang M, et al. 2012. Joint inversion of receiver functions and magnetotelluric data:Application to crustal and mantle structure beneath central Namche Barwa, eastern Himalayan syntaxis. Chinese Journal of Geophysics (in Chinese), 55(7):2281-2291, doi:10.6038/j.issn.0001-5733.2012.07.014. Qiang Z Y, Wu Q J, Li Y H, et al. 2016. Crustal anisotropy beneath central-south Mongolia and its dynamic implications. Chinese Journal of Geophysics (in Chinese), 59(5):1616-1628, doi:10.6038/cjg20160507. Savage M K. 1999. Seismic anisotropy and mantle deformation:What have we learned from shear wave splitting?. Reviews of Geophysics, 37(1):65-106. Savage M K, Wessel A, Teanby N A, et al. 2010. Automatic measurement of shear wave splitting and applications to time varying anisotropy at Mount Ruapehu Volcano, New Zealand. Journal of Geophysical Research:Solid Earth, 115(B12):B12321, doi:10.1029/2010JB007722. Shi D N, Dong Y J, Jiang M, et al. 1996. Shear wave anisotropy of the upper mantle beneath the Tingri of Tibet to Golmud of Qinghai. Acta Geologica Sinica (in Chinese), 70(4):291-297. Silver P G, Chan W W. 1991. Shear wave splitting and subcontinental mantle deformation. Journal of Geophysical Research:Solid Earth, 96(B10):16429-16454. Silver P G, Savage M K. 1994. The interpretation of shear-wave splitting parameters in the presence of two anisotropic layers. Geophysical Journal International, 119(3):949-963. Silver P G. 1996. Seismic anisotropy beneath the continents:Probing the depths of geology. Annual Review of Earth and Planetary Sciences, 24(1):385-432. Sol S, Meltzer A, Burgmann R, et al. 2007. Geodynamics of the southeastern Tibetan Plateau from seismic anisotropy and geodesy. Geology, 35(6), 563-566. 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. Tapponnier P, Xu Z Q, Roger F, et al. 2001. Oblique stepwise rise and growth of the Tibet plateau. Science, 294(5547):1671-1677. Teanby N A, Kendall J M, Van Der Baan M, et al. 2004. Automation of shear-wave splitting measurements using cluster analysis. Bulletin of the Seismological Society of America, 94(2):453-463. Teng J W, Yang D H, Tian X B, et al. 2019. Geophysical investigation progresses of the Qinghai Tibetan plateau in the past 70 years. Scientia Sinica Terrae (in Chinese), 49(10):1546-1564. Wang C Y, Chang L J, Lü Z Y, et al. 2007. Seismic anisotropy of upper mantle in eastern Tibetan Plateau and related crust-mantle coupling pattern. Science in China Series D:Earth Sciences, 50(8):1150-1160. Wang C Y, Mooney W D, Zhu L, et al. 2019. Deep structure of the eastern Himalayan collision zone:Evidence for underthrusting and delamination in the postcollisional stage. Tectonics, 38(10):3614-3628. Wang K Y, Chang L J, Ding Z F. 2021. Upper crustal anisotropy in the eastern Himalayan syntaxis. Acta Seismologica Sinica (in Chinese), 43(2):168-179. Wang M, Shen Z K. 2020. Present-day crustal deformation of continental China derived From GPS and its tectonic implications. Journal of Geophysical Research:Solid Earth, 125(2):e2019JB018774, doi:10.1029/2019JB018774. Weiss T, Siegesmund S, Rabbel W, et al. 1999. Seismic velocities and anisotropy of the lower continental crust:A review.//Seismic Exploration of the Deep Continental Crust. Basel:Birkhäuser, 97-122. Wu P, Gao Y, Chen A G, et al. 2020. Preliminary study on the anisotropy of the upper crust in the Sanjiang area, southeastern margin of the Tibetan Plateau. Chinese Journal of Geophysics (in Chinese), 63(3):1104-1116, doi:10.6038/cjg2020N0232. Xie Z X, Wu Q J, Zhang R Q. 2017. Crustal anisotropy beneath northeastern margin of the Tibetan Plateau and its dynamic implications. Chinese Journal of Geophysics (in Chinese), 60(6):2315-2325, doi:10.6038/cjg20170623. Xu Z H. 2001. A present-day tectonic stress map for eastern Asia region. Acta Seismologica Sinica (in Chinese), 23(5):492-501. Xu Z Q, Cai Z H, Zhang Z M, et al. 2008. Tectonics and fabric kinematics of the Namche Barwa terrane, Eastern Himalayan Syntaxis. Acta Petrologica Sinica (in Chinese), 24(7):1463-1476. Yin A, Harrison T M. 2000. Geologic evolution of the Himalayan-Tibetan orogen. Annual Review of Earth and Planetary Sciences, 28(1):211-280. Zhang G C, Wu Q J, Li Y J, et al. 2013. An investigation on crustal anisotropy of Northeast China using Moho Ps converted phase. Acta Seismologica Sinica (in Chinese), 35(4):485-497. Zheng T, Gao S S, Ding Z F, et al. 2021. Crustal azimuthal anisotropy and deformation beneath the northeastern Tibetan Plateau and adjacent areas:Insights from receiver function analysis. Tectonophysics, 816:229014. 附中文参考文献 常利军, 王椿镛, 丁志峰等. 2008. 青藏高原东北缘上地幔各向异性研究. 地球物理学报, 51(2):431-438. 常利军, 丁志峰, 王椿镛. 2010. 2010年玉树7.1级地震震源区横波分裂的变化特征. 地球物理学报, 53(11):2613-2619, doi:10.3969/j.issn.0001-5733.2010.11.009. 程成, 白玲, 丁林等. 2017. 利用接收函数方法研究喜马拉雅东构造结地区地壳结构. 地球物理学报, 60(8):2969-2979, doi:10.6038/cjg20170806. 丁志峰, 曾融生. 1996. 青藏高原横波分裂的观测研究. 地球物理学报, 39(2):211-220. 丁志峰, 武岩, 王辉等. 2008. 2008年汶川地震震源区横波分裂的变化特征. 中国科学(D辑:地球科学), 38(12):1600-1604. 高原, 石玉涛, 陈安国. 2018. 青藏高原东缘地震各向异性、应力及汶川地震影响. 科学通报, 63(19):1934-1948. 郭铁龙, 高原. 2020. 剪切波分裂揭示的青藏高原上地壳地震各向异性基本特征. 地球物理学报, 63(3):1085-1103, doi:10.6038/cjg2020N0156. 姜枚, 吕庆田, 史大年等. 1996. 用天然地震探测青藏高原中部地壳、上地幔结构. 地球物理学报, 39(4):438-439. 李国辉, 白玲, 丁林等. 2020. 2019年西藏墨脱MS6.3地震震源参数及其构造意义. 地球物理学报, 63(3):1214-1223, doi:10.6038/cjg2020N0231. 吕庆田, 马开义, 姜枚等. 1996. 青藏高原南部下的横波各向异性. 地震学报, 18(2):215-223. 彭淼, 谭捍东, 姜枚等. 2012. 利用接收函数和大地电磁数据联合反演南迦巴瓦构造结中部地区壳幔结构. 地球物理学报, 55(7):2281-2291, doi:10.6038/j.issn.0001-5733.2012.07.014. 强正阳, 吴庆举, 李永华等. 2016. 蒙古中南部地区地壳各向异性及其动力学意义. 地球物理学报, 59(5):1616-1628, doi:10.6038/cjg20160507. 史大年, 董英君, 姜枚等. 1996. 西藏定日-青海格尔木上地幔各向异性研究. 地质学报, 70(4):291-297. 滕吉文, 杨顶辉, 田小波等. 2019. 青藏高原深部地球物理探测70年. 中国科学:地球科学, 49(10):1546-1564. 王椿镛, 常利军, 吕智勇等. 2007. 青藏高原东部上地幔各向异性及相关的壳幔耦合型式. 中国科学(D辑:地球科学), 37(4):495-503. 王凯悦, 常利军, 丁志峰. 2021. 喜马拉雅东构造结上地壳各向异性特征. 地震学报, 43(2):168-179. 吴鹏, 高原, 陈安国等. 2020. 青藏高原东南缘三江地区上地壳各向异性初步研究. 地球物理学报, 63(3):1104-1116, doi:10.6038/cjg2020N0232. 谢振新, 吴庆举, 张瑞青. 2017. 青藏高原东北缘地壳各向异性及其动力学意义. 地球物理学报, 60(6):2315-2325, doi:10.6038/cjg20170623. 许忠淮. 2001. 东亚地区现今构造应力图的编制. 地震学报, 23(5):492-501. 许志琴, 蔡志慧, 张泽明等. 2008. 喜马拉雅东构造结——南迦巴瓦构造及组构运动学. 岩石学报, 24(7):1463-1476. 张广成, 吴庆举, 李永华等. 2013. 利用莫霍面Ps震相研究中国东北地区地壳各向异性. 地震学报, 35(4):485-497.