Structure of western Tibet from P wave teleseismic tomography
-
摘要: 采用快速行进法正演计算了西藏西部地区的远震P波理论走时，随后基于该地区台阵提取到的相对到时残差利用子空间迭代算法反演得到该地区的地壳上地幔速度相对分布。层析成像结果显示：西藏西部地区在下地壳深度显示高速异常，上地幔深度该地区内部的高速异常范围从西往东逐渐减小，且研究区域东部存在高低速异常相间分布。据此认为印度板块在青藏高原内部近水平俯冲，西部俯冲范围较大，且俯冲过程中存在板块撕裂现象，撕裂的印度板块拆沉进入上地幔，而撕裂产生的间隙由于应力释放导致了西藏西部地区新生代裂谷的形成。Abstract: In this paper, the fast marching method （FMM） is used to calculate the theoretical travel time of the teleseismic P wave in our model. We inverted the relative travel-time residuals to obtain the relative velocity distribution of crust and upper mantle in western Tibet by subspace iterative algorithm. The results show that the high-velocity anomalies exhibit in the depth of lower crust of western Tibet, while in the depth of upper mantle, the range of the high-velocity anomaly gradually decreases from west to east. And there is an alternating distribution of high- and low-velocity anomalies in the east of our study area. Therefore it is considered that the Indian Plate subducted nearly horizontally within the Tibetan Plateau, and the subduction range in the west is larger. During the subduction process, the Indian Plate is being torn. Subsequently, the torn Indian Plate sank into the upper mantle, and the tearing gap affected the formation of Cenozoic rifts in western Tibet due to stress release.
-
Keywords:
- western Tibet /
- travel-time residual /
- tomography /
- Indian Plate
-
-
![]()
图 1 西藏西部地区构造背景及本文所用台阵分布
Figure 1. Tectonic settings of western Tibet and the seismic arrays used in this study
![]()
图 2 反演所用2 191个地震事件的分布
Figure 2. Distribution of 2 191 seismic events used in this study
![]()
图 3 2007年7月18日18点01分25秒地震事件经预处理之后的波形展示
Figure 3. Seismic waveforms of an event occurred at 18:01:25 on July 18，2007 after pre-processing
![]()
图 4 自适应叠加方法效果示意图
（a） 基于AK135模型的初始对齐数据；（b） 10次迭代之后的对齐数据
Figure 4. Adaptive stacking example
（a） Alignment of initial traces given by AK135 model；（b） Alignment of final traces achieved after ten iterations
![]()
图 5 最优阻尼因子ε和光滑因子η的估计
Figure 5. Trade-off curves of optimum smoothing weight factor η and damping parameter ε
![]()
图 6 基于CRUST1.0 （a）和CRUST2.0模型（b）获得的西藏西部地区在100 km和250 km深度处的地壳层析成像结果（深度标于子图的左下角，下同）
Figure 6. Tomography results of the crust in western Tibet at the depth of 100 km and 250 km based on CRUST1.0 （a） and CRUST2.0 （b） models. The depth is labeled at the lower-left corner of each subfigure，the same below
![]()
图 7 初始模型（a）和最终模型（b）的相对到时残差分布图
Figure 7. Distribution of relative arrival time residuals for the initial （a） and final （b） models
![]()
图 8 西藏西部层析成像棋盘格测试恢复结果（左上角为对比模型）
Figure 8. Checkerboard tests in this study （The compared model is on the upper-left）
-
李天扬,李桐林,孟相禹. 2021. 基于程函方程快速行进法的地震走时层析成像法[J]. 世界地质,40(3):664–670. Li T Y,Li T L,Meng X Y. 2021. Seismic travel time tomography based on eikonal equation in fast marching method[J]. World Geology,40(3):664–670 (in Chinese).
吕庆田,姜枚,许志琴,马开义,Hirn A. 1998. 印度板块俯冲仅到特提斯喜马拉雅之下的地震层析证据[J]. 科学通报,43(12):1308–1311. Lü Q T,Jiang M,Xu Z Q,Ma K Y,Hirn A. 1998. Seismic tomographic evidence of subduction of the Indian Plate just under the Tethys Himalaya[J]. Chinese Science Bulletin,43(12):1308–1311 (in Chinese).
武振波,唐国彬,徐涛,梁春涛,翁雪飞. 2020. 印度板块下地壳北向俯冲与榴辉岩化的地震学证据:接收函数成像结果[J]. 地球物理学报,63(11):3996–4011. Wu Z B,Tang G B,Xu T,Liang C T,Weng X F. 2020. Seismological evidence for northward subduction and eclogitization of the lower crust of the Indian Plate:Receiver function results[J]. Chinese Journal of Geophysics,63(11):3996–4011 (in Chinese).
薛光琦,宿和平,钱辉,姜枚. 2006. 地震层析对印度板块向北俯冲的认识[J]. 地质学报,80(8):1156–1160. doi: 10.3321/j.issn:0001-5717.2006.08.008 Xue G Q,Su H P,Qian H,Jiang M. 2006. Seismic tomographic constraint on the northward subduction of the Indian Plate[J]. Acta Geologica Sinica,80(8):1156–1160 (in Chinese).
杨文采,江金生,瞿辰,侯遵泽,任浩然,于常青. 2019. 西藏新生代裂谷系成因的探讨[J]. 地质论评,65(2):267–279. Yang W C,Jiang J S,Qu C,Hou Z Z,Ren H R,Yu C Q. 2019. Discussion on the genesis of Cenozoic rift system in Tibet[J]. Geological Review,65(2):267–279 (in Chinese).
赵志丹,莫宣学,罗照华,周肃,董国臣,王亮亮,张凤琴. 2003. 印度—亚洲俯冲带结构:岩浆作用证据[J]. 地学前缘,10(3):149–157. doi: 10.3321/j.issn:1005-2321.2003.03.014 Zhao Z D,Mo X X,Luo Z H,Zhou S,Dong G C,Wang L L,Zhang F Q. 2003. Subduction of India beneath Tibet:Magmatism evidence[J]. Earth Science Frontiers,10(3):149–157 (in Chinese).
郑洪伟,李廷栋,高锐,赵大鹏,贺日政. 2007. 印度板块岩石圈地幔向北俯冲到羌塘地体之下的远震P波层析成像证据[J]. 地球物理学报,50(5):1418–1426. Zheng H W,Li T D,Gao R,Zhao D P,He R Z. 2007. Teleseismic P-wave tomographic evidence of the northward subduction of the lithospheric mantle of the Indian Plate beneath the Qiangtang terrane[J]. Chinese Journal of Geophysics,50(5):1418–1426 (in Chinese).
周华伟,Murphy M A,林清良. 2002. 西藏及其周围地区地壳、地幔地震层析成像:印度板块大规模俯冲于西藏高原之下的证据[J]. 地学前缘,9(4):285–292. doi: 10.3321/j.issn:1005-2321.2002.04.008 Zhou H W,Murphy M A,Lin Q L. 2002. Tomographic imaging of the Tibet and surrounding region:Evidence for wholesale underthrusting of Indian slab beneath the Tibetan Plateau[J]. Earth Science Frontiers,9(4):285–292 (in Chinese).
Bao X W,Song X D,Li J T. 2015. High-resolution lithospheric structure beneath Mainland China from ambient noise and earthquake surface-wave tomography[J]. Earth Planet Sci Lett,417:132–141. doi: 10.1016/j.jpgl.2015.02.024
Barazangi M,Ni J. 1982. Velocities and propagation characteristics of Pn and Sn beneath the Himalayan arc and Tibetan Plateau:Possible evidence for underthrusting of Indian continental lithosphere beneath Tibet[J]. Geology,10(4):179–185. doi: 10.1130/0091-7613(1982)10<179:VAPCOP>2.0.CO;2
Basuyau C,Diament M,Tiberi C,Hetényi G,Vergne J,Peyrefitte A. 2013. Joint inversion of teleseismic and GOCE gravity data:Application to the Himalayas[J]. Geophys J Int,193(1):149–160. doi: 10.1093/gji/ggs110
Ceylan S,Ni J,Chen J Y,Zhang Q,Tilmann F,Sandvol E. 2012. Fragmented Indian Plate and vertically coherent deformation beneath eastern Tibet[J]. J Geophys Res:Solid Earth,117(B11):B11303. doi: 10.1029/2012JB009210
Chen W P,Molnar P. 1981. Constraints on the seismic wave velocity structure beneath the Tibetan Plateau and their tectonic implications[J]. J Geophys Res:Solid Earth,86(B7):5937–5962. doi: 10.1029/JB086iB07p05937
Chen W P,Yang Z. 2004. Earthquakes beneath the Himalayas and Tibet: Evidence for strong lithospheric mantle[J]. Science,304:1949–1952.
Chen Y,Li W,Yuan X H,Badal J,Teng J W. 2015. Tearing of the Indian lithospheric slab beneath southern Tibet revealed by SKS-wave splitting measurements[J]. Earth Planet Sci Lett,413:13–24. doi: 10.1016/j.jpgl.2014.12.041
Copley A,McKenzie D. 2007. Models of crustal flow in the India-Asia collision zone[J]. Geophys J Int,169(2):683–698. doi: 10.1111/j.1365-246X.2007.03343.x
Dewey J F,Shackleton R M,Chang C F,Sun Y Y. 1988. The tectonic evolution of the Tibetan Plateau[J]. Philos Trans Roy Soc Lond Ser A,Math Phys Sci,327(1594):379–413.
England P,Houseman G. 1989. Extension during continental convergence,with application to the Tibetan Plateau[J]. J Geophys Res:Solid Earth,94(B12):17561–17579. doi: 10.1029/JB094iB12p17561
Hearn T M,Wang S Y,Ni J F,Xu Z H,Yu Y X,Zhang X D. 2004. Uppermost mantle velocities beneath China and surrounding regions[J]. J Geophys Res:Solid Earth,109(B11):B11301. doi: 10.1029/2003JB002874
Huang J P,Vanacore E,Niu F L,Levander A. 2010. Mantle transition zone beneath the Caribbean-South American Plate boundary and its tectonic implications[J]. Earth Planet Sci Lett,289(1/2):105–111.
Kapp P,Murphy M A,Yin A,Harrison T M,Ding L,Guo J H. 2003. Mesozoic and Cenozoic tectonic evolution of the Shiquanhe area of western Tibet[J]. Tectonics,22(4):1029. doi: 10.1029/2001TC001332
Kapp P,DeCelles P G,Gehrels G E,Heizier M,Ding L. 2007. Geological records of the Lhasa-Qiangtang and Indo-Asian collisions in the Nima area of central Tibet[J]. Geol Soc Am Bull,119(7/8):917–933.
Kind R,Yuan X,Saul J,Nelson D,Sobolev S V,Mechie J,Zhao W,Kosarev G,Ni J,Achauer U,Jiang M. 2002. Seismic images of crust and upper mantle beneath Tibet:Evidence for Eurasian Plate subduction[J]. Science,298(5596):1219–1221. doi: 10.1126/science.1078115
Kosarev G,Kind R,Sobolev S V,Yuan X,Hanka W,Oreshin S. 1999. Seismic evidence for a detached Indian lithospheric mantle beneath Tibet[J]. Science,283(5406):1306–1309. doi: 10.1126/science.283.5406.1306
Kumar P,Yuan X H,Kind R,Ni J. 2006. Imaging the colliding Indian and Asian lithospheric plates beneath Tibet[J]. J Geophys Res:Solid Earth,111(B6):B06308. doi: 10.1029/2005JB003930
Leech M L. 2008. Does the Karakoram fault interrupt mid-crustal channel flow in the western Himalaya?[J]. Earth Planet Sci Lett,276(3/4):314–322.
Li C,van der Hilst R D,Meltzer A S,Engdahl E R. 2008. Subduction of the Indian lithosphere beneath the Tibetan Plateau and Burma[J]. Earth Planet Sci Lett,274(1/2):157–168.
Li J T,Song X D. 2018. Tearing of Indian mantle lithosphere from high-resolution seismic images and its implications for lithosphere coupling in southern Tibet[J]. Proc Natl Acad Sci USA,115(33):8296–8300. doi: 10.1073/pnas.1717258115
Liang C T,Song X D. 2006. A low velocity belt beneath northern and eastern Tibetan Plateau from Pn tomography[J]. Geophys Res Lett,33(22):L22306.
Liang X F,Sandvol E,Chen Y J,Hearn T,Ni J,Klemperer S,Shen Y,Tilmann F. 2012. A complex Tibetan upper mantle:A fragmented Indian slab and no south-verging subduction of Eurasian lithosphere[J]. Earth Planet Sci Lett,333/334:101–111. doi: 10.1016/j.jpgl.2012.03.036
Meyer B,Tapponnier P,Bourjot L,Métivier F,Gaudemer Y,Peltzer G,Guo S M,Chen Z T. 1998. Crustal thickening in Gansu-Qinghai,lithospheric mantle subduction,and oblique,strike-slip controlled growth of the Tibet Plateau[J]. Geophys J Int,135(1):1–47. doi: 10.1046/j.1365-246X.1998.00567.x
Molnar P,Tapponnier P. 1975. Cenozoic tectonics of Asia:Effects of a continental collision:Features of recent continental tectonics in Asia can be interpreted as results of the India-Eurasia collision[J]. Science,189(4201):419–426. doi: 10.1126/science.189.4201.419
Molnar P,England P,Martinod J. 1993. Mantle dynamics,uplift of the Tibetan Plateau,and the Indian monsoon[J]. Rev Geophys,31(4):357–396. doi: 10.1029/93RG02030
Nábělek J,Hetényi G,Vergne J,Sapkota S,Kafle B,Jiang M,Su H P,Chen J,Huang B S,The HI-CLIMB Team. 2009. Underplating in the Himalaya-Tibet collision zone revealed by the Hi-CLIMB experiment[J]. Science,325(5946):1371–1374. doi: 10.1126/science.1167719
Peng M,Jiang M,Li Z H,Xu Z Q,Zhu L P,Chan W,Chen Y L,Wang Y X,Yu C Q,Lei J S,Zhang L S,Li Q Q,Xu L H. 2016. Complex Indian subduction style with slab fragmentation beneath the Eastern Himalayan Syntaxis revealed by teleseismic P-wave tomography[J]. Tectonophysics,667:77–86. doi: 10.1016/j.tecto.2015.11.012
Rawlinson N,Sambridge M. 2004. Wavefront evolution in strongly heterogeneous layered media using the fast marching method[J]. Geophys J Int,156(3):631–647. doi: 10.1111/j.1365-246X.2004.02153.x
Rawlinson N,Reading A M,Kennett B L N. 2006. Lithospheric structure of Tasmania from a novel form of teleseismic tomography[J]. J Geophys Res:Solid Earth,111(B2):B02301. doi: 10.1029/2005JB003803
Razi A S,Levin V,Roecker S W,Huang G C D. 2014. Crustal and uppermost mantle structure beneath western Tibet using seismic traveltime tomography[J]. Geochem Geophys Geosyst,15(2):434–452. doi: 10.1002/2013GC005143
Riaz M S,Zheng Y,Liu F,Zeng S J,Kai W,Gilani S M M. 2019. Tomographic imaging of the 2017 MS7.0 Jiuzhaigou earthquake source region and its implications on material extrusion in the northeast Tibetan Plateau[J]. Tectonophysics,752:24–34. doi: 10.1016/j.tecto.2018.12.026
Rosenbaum G,Gasparon M,Lucente F P,Peccerillo A,Miller M S. 2008. Kinematics of slab tear faults during subduction segmentation and implications for Italian magmatism[J]. Tectonics,27(2):TC2008. doi: 10.1029/2007TC002143
Sandvol E,Ni J,Kind R,Zhao W J. 1997. Seismic anisotropy beneath the southern Himalayas-Tibet collision zone[J]. J Geophys Res:Solid Earth,102(B8):17813–17823. doi: 10.1029/97JB01424
Tapponnier P,Xu Z Q,Roger F,Meyer B,Arnaud N,Wittlinger G,Yang J S. 2001. Oblique stepwise rise and growth of the Tibet Plateau[J]. Science,294(5547):1671–1677. doi: 10.1126/science.105978
Wang Z W,Zhao D P,Gao R,Hua Y Y. 2019. Complex subduction beneath the Tibetan Plateau:A slab warping model[J]. Phys Earth Planet Inter,292:42–54. doi: 10.1016/j.pepi.2019.04.007
Yin A,Harrison T M. 2000. Geologic evolution of the Himalayan-Tibetan orogen[J]. Annu Rev Earth Planet Sci,28(1):211–280. doi: 10.1146/annurev.earth.28.1.211
-
期刊类型引用(22)
1. 李金良，黄永林. 1624年“扬州地震”震中的新认识. 中国地震. 2023(02): 385-394 . 
百度学术
2. 张向格，张绪教，刘超，王鹤，刘心兰，王璐琳. 五大连池世界地质公园老黑山景区火山地震遗迹的发现及其意义. 地球学报. 2022(01): 111-122 . 百度学术
3. 赵怀群，陈文凯，张灿，康燈杰. 历史大震烈度推算新方法研究. 灾害学. 2022(02): 212-217 . 百度学术
4. 张新毅，范小露. 淮河流域中游顺治年间地震灾害考证研究. 阜阳师范大学学报(社会科学版). 2021(02): 15-20 . 百度学术
5. 秦立科，陈国栋，甄刚，周萍，贾甲，张刚，张安兴. 地震作用下馆藏石碑稳定性分析. 文博. 2021(06): 90-97 . 百度学术
6. 刁守中，刁颋，李霞，山长仑，李红. 历史强余震史料考证原则及目录校订方案探索——以1668年郯城8?级地震强余震为例. 地震科学进展. 2020(05): 22-34 . 百度学术
7. 孙柏涛，闫佳琦，李山有. 宏观地震烈度发展与其用途的演变. 地震工程与工程振动. 2019(02): 1-8 . 百度学术
8. 刁守中，刁颋，李霞，山长仑. 中国陷落地震历史资料整理与研究. 国际地震动态. 2019(06): 3-13 . 百度学术
9. 席境忆. 东汉时期的地震记录及其时空分布. 防灾科技学院学报. 2019(03): 90-95 . 百度学术
10. 郭春杉，李文巧，田勤俭，徐岳仁，杜朋，刘双. 中条山北麓断裂解州段晚更新世滑动速率研究. 地震. 2019(04): 13-26 . 百度学术
11. 闫小兵，周永胜，李自红，郭瑾. 1695年临汾73/4级地震发震构造研究. 地震地质. 2018(04): 883-902 . 百度学术
12. 王师迪，师亚芹，任凤文. 公元600年秦陇地震发震构造分析及考证研究. 地质力学学报. 2018(02): 157-168 . 百度学术
13. Li Yuche，Shi Zhenliang，Cao Xuefeng. The Large Earthquake Offshore West of Seoul, Korea, in the Southern Yellow Sea on June 22, 1518. Earthquake Research in China. 2017(04): 601-608 . 必应学术
14. 周耀，韩阳. 地震应急疏散通道的坠落物控制策略探究——以郑州二七广场德化街组团为例. 中外建筑. 2017(01): 137-140 . 百度学术
15. 张志中. 中国古建筑的防震措施探讨. 震灾防御技术. 2017(01): 194-202 . 百度学术
16. 李裕澈，时振梁，曹学锋. 1518年6月22日韩国首尔以西海域——南黄海大震. 震灾防御技术. 2017(02): 363-368 . 百度学术
17. 韩晓飞，董斌，史双双，张龙飞. 1815年平陆6(3/4)级地震两种地震烈度对比研究以及震源地现今地震环境浅析. 工程地球物理学报. 2016(02): 241-244 . 百度学术
18. 金鑫，唐艳芳，叶正伟，何燕萍，王昆婷，杨松. 近2000年来江苏地震的时空分布特征. 淮阴师范学院学报(自然科学版). 2016(01): 51-56 . 百度学术
19. 金勇强. 至道二年(996年)潼关以西至灵州地震考. 西夏研究. 2014(04): 64-67 . 百度学术
20. 王德才，倪四道，李俊. 地震烈度快速评估研究现状与分析. 地球物理学进展. 2013(04): 1772-1784 . 百度学术
21. 林国良，王健. 基于烈度点的中国历史地震资料数据库系统试编制. 地震学报. 2012(01): 118-124+127 . 本站查看
22. 金勇强. 《中国历史地震图集(远古至元时期)》所收录的宋代四次历史地震的正误. 宋史研究论丛. 2012(00): 404-422 . 百度学术
其他类型引用(22)
下载:
计量
- 文章访问数: 396
- HTML全文浏览量: 217
- PDF下载量: 74
- 被引次数: 44
