利用Lg波Q值反双台层析成像方法研究青藏高原南部地区的地壳衰减

鲁志楠, 边银菊, 王婷婷, 刘森

鲁志楠,边银菊,王婷婷,刘森. 2021. 利用Lg波Q值反双台层析成像方法研究青藏高原南部地区的地壳衰减. 地震学报,43(3):287−302. DOI: 10.11939/jass.20200051
引用本文: 鲁志楠,边银菊,王婷婷,刘森. 2021. 利用Lg波Q值反双台层析成像方法研究青藏高原南部地区的地壳衰减. 地震学报,43(3):287−302. DOI: 10.11939/jass.20200051
Lu Z N,Bian Y J,Wang T T,Liu S. 2021. Crustal attenuation in the southern Tibetan Plateau by reverse two-station Lg-wave Q value tomography. Acta Seismologica Sinica43(3):287−302. DOI: 10.11939/jass.20200051
Citation: Lu Z N,Bian Y J,Wang T T,Liu S. 2021. Crustal attenuation in the southern Tibetan Plateau by reverse two-station Lg-wave Q value tomography. Acta Seismologica Sinica43(3):287−302. DOI: 10.11939/jass.20200051

利用Lg波Q值反双台层析成像方法研究青藏高原南部地区的地壳衰减

基金项目: 核查项目(075440)资助
详细信息
    通讯作者:

    边银菊: e-mail:bianyinju@cea-igp.ac.cn

  • 中图分类号: P315.3+1

Crustal attenuation in the southern Tibetan Plateau by reverse two-station Lg-wave Q value tomography

  • 摘要: 首次基于2017—2019年西藏自治区区域台网27个宽频带固定台站记录的757次地震的波形资料,利用反双台法开展了青藏高原南部地区1 Hz的Lg波Q值层析成像研究。研究中采用3.5—2.4 km/s的速度窗截取了1 981条Lg波,计算得到13 543条路径上的Q值,测试了1°×1°和0.5°×0.5°网格下的棋盘格恢复情况,得到了0.5°×0.5°分辨率的Lg波Q0值层析成像。反演结果显示:青藏高原南部地壳整体的Lg波呈高衰减、低Q值,与P波速度负异常、地热分布及东部的两条裂谷系对应良好,因此推断青藏高原南部地壳存在广泛的熔融物质;两条可能存在的流体-熔融物质通道中,主通道位于亚东—谷露裂谷与桑日—错那裂谷之间,副通道沿雅鲁藏布江缝合带分流而出。此外,还对亚东—谷露裂谷两侧熔融物质的分布差异予以分析,结果表明,印度板块与欧亚板块碰撞前端存在不同的动力学演化模式,亚东—谷露裂谷以西符合缩短增厚理论,以东符合“水泵”模式。
    Abstract: Based on the seismic waveform data of 757 earthquakes recorded by 27 broadband stations of Tibet Autonomous Region seismic network from 2017 to 2019, it is for the first time that the reverse two-station method has been applied to 1 Hz Lg-wave Q value tomography study in the southern Tibetan Plateau. In this research, total 1 981 Lg-waves were intercepted from the velocity window of 3.5−2.4 km/s and the Q values of 13 543 paths were calculated. After testing the checkerboard recovery of 1°×1° and 0.5°×0.5° grids respectively, we got the tomography of the Lg-wave Q0 value of the southern Tibetan Plateau with 0.5°×0.5° resolution. The inversion result shows that there exhibits high attenuation and low Q values of Lg-wave in the southern Tibetan Plateau crust, which is highly consistent with the negative anomaly of P-wave velocity, the geothermal distribution and two rift valleys in the east of the Tibet. Therefore it is inferred that there may be widespread molten material in the crust of the southern Tibetan Plateau and two fluid-melting channels. The main channel is located between the Yadong-Gulu rift and the Sangri-Cona rift, and the secondary channel flows out along the Yarlung Zangbo suture zone. By analyzing the differences of molten material distribution on both sides of the Yadong-Gulu rift, it is considered that there are different dynamical evolution models in the front-end of collision between Indian Plate and Eurasian Plate, the dynamical evolution to the west of Yadong-Gulu rift is in accordance with the theory of shortening and thickening, and that to the east of Yadong-Gulu rift is consistent with the “pump” mode.
  • 对于地震学而言,高频全球导航卫星系统(global navigation satellite system,简写为GNSS)是能够记录到地震波传播信息的一种新手段,其在强震中可直接提供时变位移场观测信息,弥补了传统观测手段在强震观测时出现诸如震级饱和、漂移等现象的不足。但由于高频GNSS数据存在信噪比低、信号稳定性差等问题,在预警中需要与测/强震观测手段联合使用。地震波信号往往是一种非线性、非平稳信号,故研究其频率的局部特性显得至关重要,这就需要用时频分析方法将一维时域信号转换到二维的时频平面。而傅里叶变换和反变换虽然能从时间域和频率域对平稳信号进行分析,却不能同时保留时间和频率信息。故此,本文拟以2008年汶川地震时获取的高频GNSS同震信号为例,通过对其进行广义S变换,系统分析变换后同震信号的时间域和频率域,以期能够更加准确地判断P波和S波到时。同时,广义S变换的使用也为高频GNSS在地震学中的应用提供了一条从多层面提取地震波形到时的新途径。

    美国地球物理学家Stockwell等(1996)综合了小波变换和短时傅里叶变换的特点,提出了一种分析非平稳信号的新方法—S变换。其时频随着频率的不同而变化,具有多分辨率、逆变换唯一等特点,同时获得的二维时频谱也是基于傅里叶变换的基本理论。该方法已经在地震勘探、电能信号分析、故障检测等多个领域得到了广泛的应用(齐春燕等,2010周竹生,陈友良,2011郑成龙,王宝善,2015)。

    S变换的表示形式为

    $$ {{S}}(\tau {\text{,}}f) {\text{=}} \int _{ {\text{-}} \infty }^{ {\text{+}} \infty }h(t)\left\{ {\frac{{|f|}}{{\sqrt {2\pi } }}\exp \left[\frac{{ {\text{-}} {f^2}{{(t {\text{-}} \tau )}^2}}}{2}\right]\exp ( {\text{-}} {\rm i}2\pi ft)} \right\}{\rm d}t{\text{,}} $$ (1)

    式中:τ为窗函数的中心点,控制窗函数在时间轴上的位置;f为采样频率;ht)为原始信号。S变换使用的高斯窗函数gft)和基本小波ωft)分别定义为

    $$ {{g}_f}(t) {\text{=}} \frac{{|f|}}{{\sqrt {2\pi } }}\exp \left({\text{-}} \frac{{{t^2}{f^2}}}{2}\right){\text{,}} $$ (2)
    $$ {\omega _f}(t) {\text{=}} \frac{{|f|}}{{\sqrt {2\pi } }}\exp \left( {\text{-}} \frac{{{t^2}{f^2}}}{2} {\text{-}} {\rm i}2\pi ft\right) {\text{=}} {g_f}(t)\exp ( {\text{-}} {\rm i}2\pi ft){\text{,}} $$ (3)

    从上式可以看到,S变换在分析高频信号或低频信号时具有良好的特性:对于高频信号,设计窗口比较窄,可满足高时间分辨率的要求;对于低频信号,设计窗口比较宽,可满足高频率分辨率的要求。

    相比于单分辨率的短时傅里叶变换,S变换属于多分辨率时频分析方法,可以更加有效地对复杂的地震波信号进行分析。同时由于信号xt)可以由S变换Sτf )通过逆变换进行重构,Sτf )的S逆变换为

    $$ {\rm{x}}(t) {\text{=}} \int_{ {\text{-}} \infty }^{ {\text{+}} \infty } {\left[ {\int_{ {\text{-}} \infty }^{ {\text{+}} \infty } {S(\tau{\text{,}} f\;)\rm d\tau } } \right]} \exp ({\rm i}2\pi ft){\rm {d}}f{\text{,}} $$ (4)

    S变换所具有的无损逆变换的特性,使得信号在经过时频域处理后可逆变换为时间信号。

    由于S变换的基本高斯窗函数固定,因此在处理复杂的地震信号时,不能根据需求对频率域和时间域的分辨率进行调节,缺乏必要的灵活性。随着后期的不断发展,多位研究人员对S变换中的高斯窗函数和基本小波进行改变,构建出了广义的S变换(Mansinha等,1997McFadden et al,1999高静怀等,2003Pinnegar,Mansinha ,2003陈学华等,2006齐春燕等,2010周竹生,陈友良,2011)。

    本文使用的广义S变换是通过两个调节因子对高斯窗进行改造(陈学华等,2006),以便根据实际要求对高斯窗作出调整,从而更好地分析复杂频率的地震波形,其表达式为

    $$ {{S}}(\tau {\text{,}} f) {\text{=}} \int\nolimits_{ {\text{-}} \infty }^\infty {x(t)\frac{{|{\lambda _{\rm a}}||f{|^p}}}{{2\pi }}} {{\rm exp}({\frac{{ {\text{-}} {\lambda ^2_{\rm{a}}}{f^{2p}}{{(t {\text{-}} \tau )}^2}}}{2}}}){{\rm exp}({ {\text{-}} {\rm i}2\pi ft}}){\rm d}t{\text{,}} $$ (5)

    式中λap均为调节因子。选定p值后,当λa>1时,时窗宽度随频率呈反比变化的速度加快;当λa<1时,时窗宽度随频率呈反比变化的速度减慢;选定λa之后,通过调节p值可以对频率域的分辨率进行调整。引入λap两个参数之后,可以根据实际信号的频率分布特点和时频分析的侧重点,改变高斯窗函数随频率变化的规律,对时频分辨率进行调整,但由于其运算过程与标准的S变换相似,因此并不需要额外增加运算量。当两个调节因子λap均设置为1时,则为标准S变换。

    本文收集了2008年汶川MS8.0地震中重庆台网和昆明台网共28个站点的高频GNSS信号(采样率为1 Hz),采用GAMIT/GLOBK软件包(Bock,2000)中的高频GNSS处理模块TRACK (Chen,1998)对附近站点的高频GNSS数据进行解算。由于所选取数据按小时文件进行解算,时间最长为1小时,故未考虑昼夜变化等周期性较长的噪音。按照GNSS站点的位置及分布情况,选取15个站点的数据使用广义S变换进行分析,并挑选其中6个站点的同震波形进行展示,如图1所示。

    图  1  部分站点的高频GNSS同震波形展示
    Figure  1.  Coseismic waveforms of high-rate GNSS from some sites

    根据距离震中位置的远近选取了bana (距震中约346 km)、djxm (距震中381 km)、fdlh (距震中477 km)和ghxx (距震中661 km)等4个站点的同震波形,对其进行广义S变换后识别出P波、S波到时并进行展示(图1),在计算P波和S波的理论到时中使用了频率-波数法(Zhu,2002),计算到时的速度模型为一维速度模型(吴建平等,2009殷海涛等,2013邓文哲等,2014王小娜等,2015杨彦明等,2016)。

    bana站点距离震中346 km,该站点记录高频GNSS信号的频率为1 Hz,根据奈奎斯特(Nyquist)采样定理,其可记录到的地震波信号的最大频率为0.5 Hz。bana站点东西向同震信号广义S变换的结果表明(图2),地震信号的能量主要集中于0—0.3 Hz,所研究各站点的P波和S波理论到时均在300 s以内。为了更加直观地显示所研究的到时区域,在后续分析中,按照S变换后信号频率为0—0.3 Hz,取地震发生后的300 s进行分析。结果显示,bana站点的P波理论到时为56.7 s,S波理论到时为96.1 s。如图1所示,经过广义S变换后的图像显示,在P波和S波理论到时(图2)的位置,均有着较明显的能量汇集。在本文分析的地震中,P波和S波周期均较长、频率均相近,故P波的识别周期为20—50 s左右的初至拾取、高于背景噪声的能量汇集,S波能量为P波能量的2.5倍以上(水平向)。

    图  2  bana站点东西向同震信号的S变换结果
    Figure  2.  S transform of coseismic signal in the EW directionin at the bana station

    在使用广义S变换进行频率分析时,通过对两个调节因子λap进行调整,以获得最优的分辨率。以bana站东西向为例进行分析,结果如图3所示。

    图  3  通过微调调节因子λap所产生的同震信号广义S变换结果展示
    Figure  3.  S transform results of the same coseismic signal with different adjustment factor λa and p
    (a) λa=1,p=1.1;(b) λa=1,p=1.2;(c) λa=1.05,p=1.05;(d) λa=1.05,p=1.05

    λa不变的情况下,提高因子p值,可以增加时间域的分辨率,详见图2图3a。但是p值过高,会导致频率域的分辨率增加,时间域的分辨率降低,从而降低了对初至波的识别能力(图3b)。当调节因子λa=1.05,p=1.05时,对于P波和S波的识别均较为清晰。图3d图3c进行三维展示,更加直观地展示了震后随着时间的变化,不同周期的波形所汇聚的能量大小。

    对于震中距为381 km的djxm站点,其P波理论到时为62.5 s,S波理论到时为105.9 s。将P波和S波理论到时分别标注于S变换结果上(选用的调节因子为λa=1.05,p=1.05),可以看出,在同震信号中,djxm站记录的到时要比理论到时延迟约4—5 s (图4a),可能与本文使用的速度结构有一定关系,而djxm站在垂向上很难识别S波到时(图4b)。在原始波形记录中,无论垂直向还是水平向均已很难判定P波和S波到时。这表明通过微调广义S变换的两个调节因子λap,能够得到较好的到时分辨率。鉴于目前GNSS预警中的触发方式为阈值触发(Allen,Ziv,2011Melgar et al,2012),很难通过反演的方式进行精确的震源定位。而相比于人工或者阈值判断,通过对地震信号进行广义S变换,能够对到时作出更为精准的判断。

    图  4  各高频GNSS站点同震信号S变换结果展示
    (a) djxm站点EW向同震信号S变换;(b) djxm站点UD向同震信号S变换;(c) fdlh站点EW向同震信号S变换;(d) fdlh站点UD向同震信号S变换;(e) ghxx站点EW向同震信号S变换;(f) ghxx站点UD向同震信号S变换
    Figure  4.  S treansform of coseismic signals for several stations
    (a) S transform of EW coseismic signal in djxm;(b) S transform of UD coseismic signal in djxm;(c) S transform of the EW coseismic signal in fdlh ;(d) S transform of the UD coseismic signal in fdlh;(e) S transform of the EW coseismic signal in ghxx;(f) S transform of the UD coseismic signal in ghxx

    对于震中距为477 km的fdlh站,P波和S波理论到时分别为79 s和133 s。东西向同震信号的广义S变换(选用的调节因子为λa=1.05,p=1.05)波形识别基本与理论到时一致,相差2—3 s (图4c)。fdlh站垂直向上的分辨率也可以满足波形识别的需求(图4d)。其结果较好,可能与fdlh站的背景噪声较低有关。三维图像中,面波的识别更加清晰(图4c)。

    对于震中距为661 km的ghxx站,在同震信号中很难看到P波到时和S波到时。经过计算,其P波理论到时为108.3 s,S波理论到时为183 s。在图4e中可以看到,通过广义S变换后对S波的识别较好,对P波的识别稍显模糊。而对于垂直向(图4f),通过广义S变换之后,P波已经无法识别,S波的识别时间较理论地震波形要晚将近20 s。这可能与GNSS背景噪声较高,且垂直向的噪音水平高于水平向2—3倍有关。而同震信号的分析中,P波和S波的到时基本均无法分辨。这说明通过广义S变换,即使是震中距大于600 km,也能有效地提取到地震波到时。

    对于实时解算的高频GNSS数据,其背景噪声相对较大,使用广义S变换,可以更加准确地得到P波到时。即使远距离的站点记录,在时频域中也可以很好地指示出P波初至到时。这为高频GNSS数据在地震学中的应用和分析提供了一种新的途径。其优势在于:

    1) 广义S变换集合了短时傅里叶变换和小波变换的优点,在地球物理领域及电能分析领域取得了很多成果,但依旧存在很多应用前景。本文通过对高频GNSS同震信号进行S变换,从以往的只针对单独的时间域或频率域分析高频GNSS信号,转变为从时间域和频率域同时进行分析。从频率域的角度看,P波和S波的能量均汇聚于0.025 Hz左右,面波的能量汇聚于0.04—0.25 Hz并能够明显地看出面波是分为多个频率区间;从时间域的角度看,P波和S波的理论到时均有明显的能量汇集,而面波到时则更加明显。通过对不同频率的信号进行分析,认为近震范围内P波和S波实际到时与理论到时的分辨率相差仅为1—2 s,中远震其分辨率相差3—5 s,该方法可以作为高频GNSS信号的分析及各类波形到时的提取手段。

    2) 通过对高频GNSS信号使用S变换可见,有效信号与噪音信号的分离较为明显,说明S变换在降噪去噪方面具有独特的优势。鉴于信号可以进行无损S变换和S逆变换,因此可以使用该方法提高高频GNSS信号的信噪比,尤其是在压制噪音方面具有很大的优势,下一步研究中将根据各波形的到时按时间提取波形并用于专门性的分析。

    感谢两位审稿专家对本文提出的意见和建议。

  • 图  1   青藏高原南部地区缝合带和地体的分布(蓝色矩形为本文研究区域)

    Figure  1.   Suture zones and terranes distribution in the southern Tibetan Plateau(The blue box is the research area of this study)

    图  2   反双台法几何路径示意图

    (a) 理想条件下;(b) 实际条件下

    Figure  2.   Schematic diagram for the geometry of the reverse two-station method

    (a) An ideal recording geometry;(b) A more practical geometry

    图  3   本文反双台法计算所用台站及地震事件的分布

    Figure  3.   Distribution of seismic stations and earthquakes calculated by reverse two-station method in this paper

    图  4   Pn波与Lg波窗口的拾取实例

    Figure  4.   An example showing the Pn-waves and the window of Lg-waves

    图  5   每个网格经过的Q0射线数量

    Figure  5.   Number of Q0 rays per grid

    图  6   Q0射线分布直方图

    Figure  6.   Q0 values distribution histogram

    图  7   1°×1° (a)和0.5°×0.5° (b)网格下的棋盘格测试结果

    Figure  7.   The checkerboard test results with gridding of 1°×1° (a) and 0.5°×0.5° (b)

    图  8   青藏高原南部地区Lg波Q0值层析成像

    Figure  8.   Lg-wave Q0 value tomography of the southern Tibetan Plateau

    图  9   青藏高原南部熔融通道(红色实线区域)的推断示意图

    Ⅰ ,Ⅱ ,Ⅲ和Ⅳ代表四个由雅鲁藏布江缝合带和亚东—谷露裂谷划分的地块

    Figure  9.   The inference of melting channels in the southern Tibetan Plateau

    The area delineated by red solid lines denotes melting channels,and the symbols of Ⅰ ,Ⅱ ,Ⅲ and Ⅳ represent four blocks separated by the Yarlung Zangbo suture and Yadong-Gulu rift

  • 艾印双,郑天愉. 1997. 青藏高原地震活动及其构造背景[J]. 地球物理学进展,12(2):30–40.

    Ai Y S,Zheng T Y. 1997. Seismic activity in Tibetan Plateau and its tectonic implication[J]. Progress in Geophysics,12(2):30–40 (in Chinese).

    白嘉启,梅琳,杨美伶. 2006. 青藏高原地热资源与地壳热结构[J]. 地质力学学报,12(3):354–362. doi: 10.3969/j.issn.1006-6616.2006.03.010

    Bai J Q,Mei L,Yang M L. 2006. Geothermal resource and crustal thermal structure of the Qinghai-Tibet Plateau[J]. Journal of Geomechanics,12(3):354–362 (in Chinese).

    才巴央增,赵俊猛. 2018. 藏南裂谷系的研究综述[J]. 地震研究,41(1):14–21. doi: 10.3969/j.issn.1000-0666.2018.01.002

    Caibayangzeng,Zhao J M. 2018. A summary of researches on southern Tibet rift system[J]. Journal of Seismological Research,41(1):14–21 (in Chinese).

    冯昭贤,赵文津. 1997. INDEPTH与INDEPTH-MT项目简介[J]. 现代地质,11(3):363–365.

    Feng Z X,Zhao W J. 1997. Simple introduction to project INDEPTH and subproject NDEPTH-MT[J]. Geoscience,11(3):363–365 (in Chinese).

    何静,吴庆举,李永华,雷建设. 2017. 天然地震Lg波衰减研究进展及其在中国大陆地区的应用[J]. 地球物理学进展,32(2):466–475. doi: 10.6038/pg20170204

    He J,Wu Q J,Li Y H,Lei J S. 2017. Developments of earthquake Lg-wave attenuation study and its application in the continental China[J]. Progress in Geophysics,32(2):466–475 (in Chinese).

    李仕虎,黄宝春,朱日祥. 2012. 青藏高原东南缘构造旋转的古地磁学证据[J]. 地球物理学报,55(1):76–94. doi: 10.6038/j.issn.0001-5733.2012.01.008

    Li S H,Huang B C,Zhu R X. 2012. Paleomagnetic constraints on the tectonic rotation of the southeastern margin of the Tibetan Plateau[J]. Chinese Journal of Geophysics,55(1):76–94 (in Chinese). doi: 10.1002/cjg2.1702

    李永华,吴庆举. 2007. 中国地学热点研究区几个地学问题的探讨[J]. 国际地震动态,(9):11–19. doi: 10.3969/j.issn.0253-4975.2007.09.003

    Li Y H,Wu Q J. 2007. Study on some “Hot Spot” areas of geo-sciences in China[J]. Recent Developments in World Seismology,(9):11–19 (in Chinese).

    李娱兰. 2019. 青藏高原地震活动性及冈底斯成矿带东段上地幔顶部Pn波速度结构[D]. 北京: 中国地震局地球物理研究所: 1–8.

    Li Y L. 2019. Seismicity of the Qinghai-Tibet Plateau and Velocity Structure of Pn Wave on the Top of the Upper Mantle in the Eastern Gangdise Metallogenic Belt[D]. Beijing: Institute of Geophysics, China Earthquake Administration: 1–8 (in Chinese).

    刘建华,刘福田,阎晓蔚,胥颐,郝天珧. 2004. 华北地区Lg尾波衰减研究:Lg尾波Q0地震成像[J]. 地球物理学报,47(6):1044–1052. doi: 10.3321/j.issn:0001-5733.2004.06.017

    Liu J H,Liu F T,Yan X W,Xu Y,Hao T Y. 2004. A study of Lg coda attenuation beneath North China:Seismic imaging Lg coda Q0[J]. Chinese Journal of Geophysics,47(6):1044–1052 (in Chinese).

    吴中海,叶培盛,王成敏,张克旗,赵华,郑勇刚,尹金辉,李虎侯. 2015. 藏南安岗地堑的史前大地震遗迹、年龄及其地质意义[J]. 地球科学:中国地质大学学报,40(10):1621–1642.

    Wu Z H,Ye P S,Wang C M,Zhang K Q,Zhao H,Zheng Y G,Yin J H,Li H H. 2015. The relics,ages and significance of prehistoric large earthquakes in the Angang graben in south Tibet[J]. Earth Science:Journal of China University of Geosciences,40(10):1621–1642 (in Chinese). doi: 10.3799/dqkx.2015.147

    喻成,乔学军,王伟,史永明. 2014. 亚东—谷露裂谷带与块体运动的特征[J]. 大气测量与地球动力学,34(2):36–40.

    Yu C,Qiao X J,Wang W,Shi Y M. 2014. Characteristics of crust deformation in Yadong-Gulu rift and its surrounding areas with GPS data[J]. Journal of Geodesy and Geodynamics,34(2):36–40 (in Chinese).

    张戈铭,李细兵,郑晨,宋晓东. 2019. 青藏高原中东部地壳和上地幔顶部P波层析成像[J]. 地震学报,41(4):411–424. doi: 10.11939/jass.20190003

    Zhang G M,Li X B,Zheng C,Song X D. 2019. Crustal and uppermost mantle velocity structure beneath the central eastern Tibetan Plateau from P-wave tomography[J]. Acta Seismologica Sinica,41(4):411–424 (in Chinese).

    张衡,赵俊猛,徐强. 2011. 西藏东部地区层析成像及东南部裂谷成因讨论[J]. 科学通报,56(27):2328–2334.

    Zhang H,Zhao J M,Xu Q. 2011. Seismic P-wave tomography in eastern Tibet:Formation of the rifts[J]. Chinese Science Bulletin,56(23):2450–2455. doi: 10.1007/s11434-011-4577-x

    张红亮. 2010. 藏北水热活动的地质背景研究[D]. 北京: 中国地质大学(北京): 13–17.

    Zhang H L. 2010. Study on the Geological Background of Hydrothermal Activities in North Tibet[D]. Beijing: China University of Geosciences (Beijing): 13–17 (in Chinese).

    张锦玲,朱新运,马起杨. 2019. 宁夏地区Lg波衰减及场地响应特征[J]. 地震学报,41(4):425–434. doi: 10.11939/jass.20180134

    Zhang J L,Zhu X Y,Ma Q Y. 2019. Lg-wave attenuation and site response in Ningxia region[J]. Acta Seismologica Sinica,41(4):425–434 (in Chinese).

    赵连锋,谢小碧,王卫民,姚振兴. 2018. 中国东北和朝鲜半岛地区地壳Lg波宽频带衰减模型[J]. 地球物理学报,61(3):856–871. doi: 10.6038/cjg2018L0394

    Zhao L F,Xie X B,Wang W M,Yao Z X. 2018. A broadband crustal Lg wave attenuation model in Northeast China and the Korean Peninsula[J]. Chinese Journal of Geophysics,61(3):856–871 (in Chinese).

    赵文津,吴珍汉,史大年,熊嘉育,薛光琦,宿和平,胡道功,叶培盛. 2008. 国际合作INDEPTH项目横穿青藏高原的深部探测与综合研究[J]. 地球学报,29(3):328–342. doi: 10.3321/j.issn:1006-3021.2008.03.007

    Zhao W J,Wu Z H,Shi D N,Xiong J Y,Xue G Q,Su H P,Hu D G,Ye P S. 2008. Comprehensive deep profiling of Tibetan Plateau in the INDEPTH project[J]. Acta Geoscientica Sinica,29(3):328–342 (in Chinese).

    周蕙兰. 1990. 地球内部物理[M]. 北京: 地震出版社: 218–237.

    Zhou H L. 1990. Physics of the Earths Interior[M]. Beijing: Seismological Press: 218–237 (in Chinese).

    周连庆,赵翠萍,修济刚,陈章立. 2008a. 川滇地区Lg波Q值层析成像[J]. 地球物理学报,51(6):1745–1752.

    Zhou L Q,Zhao C P,Xiu J G,Chen Z L. 2008a. Tomography of Q Lg in Sichuan-Yunnan zone[J]. Chinese Journal of Geophysics,51(6):1745–1752 (in Chinese).

    周连庆,赵翠萍,修济刚,陈章立,郑斯华. 2008b. 利用天然地震研究地壳Q值的方法和进展[J]. 国际地震动态,(2):1–11.

    Zhou L Q,Zhao C P,Xiu J G,Chen Z L,Zheng S H. 2008b. Methods and developments of research on crustal Q value by using earthquakes[J]. Recent Developments in World Seismology,(2):1–11 (in Chinese).

    朱新运. 2016. 华北盆地Lg波衰减及台站场地响应特征[J]. 地球科学,41(12):2109–2117.

    Zhu X Y. 2016. Characteristics of Lg wave attenuation and site response in North China basin[J]. Earth Science,41(12):2109–2117 (in Chinese).

    Al-Damegh K,Sandvol E,Al-Lazki A,Barazangi M. 2004. Regional seismic wave propagation (Lg and Sn) and Pn attenuation in the Arabian Plate and surrounding regions[J]. Geophys J Int,157(2):775–795. doi: 10.1111/j.1365-246X.2004.02246.x

    Armijo R,Tapponnier P,Han T. 1989. Late Cenozoic right-lateral strike-slip faulting in southern Tibet[J]. J Seismol Res,94(B3):2787–2838.

    Bao X Y,Sandvol E,Ni J,Hearn T,Chen Y J,Shen Y. 2011a. High resolution regional seismic attenuation tomography in eastern Tibetan Plateau and adjacent regions[J]. Geophys Res Lett,38(16):L16304.

    Bao X Y,Sandvol E,Zor E,Sakin S,Mohamad R,Gök R,Mellors R,Godoladze T,Yetirmishli G,Türkelli N. 2011b. Pg attenuation tomography within the northern Middle East[J]. Bull Seismol Soc Am,101(4):1496–1506. doi: 10.1785/0120100316

    Brown L D,Zhao W,Nelson K D,Hauck M,Alsdorf D,Ross A,Cogan M,Clark M,Liu X,Che J. 1996. Bright spots,structure,and magmatism in southern Tibet from INDEPTH seismic reflection profiling[J]. Science,274(5293):1688–1690. doi: 10.1126/science.274.5293.1688

    Campillo M,Plantet J L,Bouchon M. 1985. Frequency-dependent attenuation in the crust beneath central France from Lg waves:Data analysis and numerical modeling[J]. Bull Seismol Soc Am,75(5):1395–1411.

    Chen Q Z,Freymueller J T,Wang Q,Yang Z Q,Xu C J,Liu J N. 2004. A deforming block model for the present‐day tectonics of Tibet[J]. J Geophys Res,109(B1):B01403.

    England P C,Houseman G A. 1988. The mechanics of the Tibetan Plateau[J]. Phil Trans R Soc Lond A,326(1589):301–320. doi: 10.1098/rsta.1988.0089

    Fan G W,Lay T. 2002. Characteristics of Lg attenuation in the Tibetan Plateau[J]. J Geophys Res,107(B10):2256.

    Fan G W,Lay T. 2003. Strong Lg attenuation in the northern and eastern Tibetan Plateau measured by a two-station/two-event stacking method[J]. Geophys Res Lett,30(10):1530.

    Ford S R,Dreger D S,Mayeda K,Walter W R,Malagnini L,Phillips W S. 2008. Regional attenuation in northern California:A comparison of five 1D Q methods[J]. Bull Seismol Soc Am,98(4):2033–2046. doi: 10.1785/0120070218

    Gök R,Sandvol E,Türkelli N,Seber D,Barazangi M. 2003. Sn attenuation in the Anatolian and Iranian Plateau and surrounding regions[J]. Geophys Res Lett,30(24):8042.

    Herrmann R B. 1980. Q estimates using the coda of local earthquake[J]. Bull Seismol Soc Am,70(4):447–468.

    Hu S B,He L J,Wang J Y. 2000. Heat flow in the continental area of China:A new data set[J]. Earth Planet Sci Lett,179(2):407–419. doi: 10.1016/S0012-821X(00)00126-6

    Li S H,Unsworth M J,Booker J R,Wei W B,Tan H D,Jones A G. 2003. Partial melt or aqueous fluid in the mid-crust of southern Tibet?Constraints from INDEPTH magnetotelluric data[J]. Geophys J Int,153(2):289–304. doi: 10.1046/j.1365-246X.2003.01850.x

    McNamara D T,Owens T J,Walter W R. 1996. Propagation characteristics of Lg across the Tibetan Plateau[J]. Bull Seismol Soc Am,86(2):457–469.

    Mitchell B J. 1980. Frequency dependence of shear wave internal friction in the continental crust of eastern North America[J]. J Geophys Res,85(B10):5212–5218. doi: 10.1029/JB085iB10p05212

    Myers S C,Beck S,Zandt G,Wallace T. 1998. Lithospheric-scale structure across the Bolivian Andes from tomographic images of velocity and attenuation for P and S waves[J]. J Geophys Res,103(B9):21233–21252. doi: 10.1029/98JB00956

    Nelson K D,Zhao W J,Brown L D,Kuo J,Che J K,Liu X W,Klemperer S L,Makovsky Y,Meissner R,Mechie J,Kind R,Wenzel F,Ni J,Nabelek J,Leshou C,Tan H D,Wei W B,Jones A G,Booker J,Unsworth M,Kidd W S F,Hauck M,Alsdorf D,Ross A,Cogan M,Wu C D,Sandvol E,Edwards M. 1996. Partially molten middle crust beneath southern Tibet:Synthesis of project INDEPTH results[J]. Science,274(5293):1684–1688. doi: 10.1126/science.274.5293.1684

    Ni J,Barazangi M. 1983. High-frequency seismic wave propagation beneath the Indian shield,Himalayan arc,Tibetan Plateau and surrounding regions:High uppermost mantle velocities and efficient Sn propagation beneath Tibet[J]. Geophys J R astr Soc,72(3):665–689. doi: 10.1111/j.1365-246X.1983.tb02826.x

    Nuttli O W. 1980. The excitation and attenuation of seismic crustal phases in Iran[J]. Bull Seismol Soc Am,70(2):469–485.

    Paige C C,Saunders M A. 1982. LSQR:An algorithm for sparse linear equations and sparse lest squares[J]. ACM Trans Math Software,8(1):43–71. doi: 10.1145/355984.355989

    Phillips W S,Hartse H E,Taylor S R,Randall G E. 2000. 1 Hz Lg Q tomography in central Asia[J]. Geophys Res Lett,27(20):3425–3428. doi: 10.1029/2000GL011482

    Press F,Ewing M. 1952. Two slow surface waves across North America[J]. Bull Seismol Soc Am,42(3):219–228. doi: 10.1785/BSSA0420030219

    Reese C C,Rapine R R,Ni J F. 1999. Lateral variation of Pn and Lg attenuation at the CDSN station LSA[J]. Bull Seismol Soc Am,89(1):325–330. doi: 10.1785/BSSA0890010325

    Ringdal F,Marshall P D,Alewine R W. 1992. Seismic yield determination of Soviet underground nuclear explosions at the Shagan River test site[J]. Geophys J Int,109(1):65–77. doi: 10.1111/j.1365-246X.1992.tb00079.x

    Ruzaikin A I,Nersesov I L,Khalturin V I,Molnar P. 1977. Propagation of Lg and lateral variations in crustal structure in Asia[J]. J Geophys Res,82(2):307–316. doi: 10.1029/JB082i002p00307

    Sato R. 1967. Attenuation of seismic waves[J]. J Phys Earth,15(2):32–61. doi: 10.4294/jpe1952.15.32

    Shin T C,Herrmann R B. 1987. Lg attenuation and source studies using 1982 Miramichi data[J]. Bull Seismol Soc Am,77(2):384–397.

    Singh C,Shekar M,Singh A,Chadha R K. 2012. Seismic attenuation characteristics along the Hi-CLIMB profile in Tibet from Lg Q inversion[J]. Bull Seismol Soc Am,102(2):783–789. doi: 10.1785/0120110145

    Singh S,Herrmann R B. 1983. Regionalization of crustal coda Q in the continental United States[J]. J Geophys Res,88(B1):527–538. doi: 10.1029/JB088iB01p00527

    Tapponnier P,Mercier J L,Armijo R,Han T L,Zhou J. 1981. Field evidence for active normal faulting in Tibet[J]. Nature,294(5840):410–414. doi: 10.1038/294410a0

    Tapponnier P,Peltzer G,Le Dain A Y,Armijo R,Cobbold P R. 1982. Propagating extrusion tectonics in Asia:New insights from simple experiments with plasticine[J]. Geology,10(12):611–616. doi: 10.1130/0091-7613(1982)10<611:PETIAN>2.0.CO;2

    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

    USGS. 2019. Search earthquake catalog[EB/OL]. [2019-09-01]. https://earthquake.usgs.gov/earthquakes/search.

    Wei W B,Unsworth M,Jones A,Booker J,Tan H D,Nelson D,Chen L S,Li S H,Solon K,Bedrosian P,Jin S,Deng M,Ledo J,Kay D,Roberts B. 2001. Detection of widespread fluids in the Tibetan crust by magnetotelluric studies[J]. Science,292(5517):716–719. doi: 10.1126/science.1010580

    Xie J. 2002. Lg Q in the eastern Tibetan Plateau[J]. Bull Seismol Soc Am,92(2):871–876. doi: 10.1785/0120010154

    Xie J,Mitchell B J. 1990a. Attenuation of multiphase surface waves in the Basin and Range Province,part I:Lg and Lg coda[J]. Geophys J Int,102(1):121–137. doi: 10.1111/j.1365-246X.1990.tb00535.x

    Xie J,Mitchell B J. 1990b. A back-projection method for imaging large-scale lateral variations of Lg coda Q with application to continental Africa[J]. Geophys J Int,100(1):161–181.

    Xie J,Gok R,Ni J,Aoki Y. 2004. Lateral variations of crustal seismic attenuation along the INDEPTH profiles in Tibet from Lg Q inversion[J]. J Geophys Res,109(B10):B10308.

    Xie J K. 1998. Spectral inversion using Lg from earthquakes:Improvement of the method with applications to the 1995,western Texas earthquake sequence[J]. Bull Seismol Soc Am,88(6):1525–1537.

    Yang X N. 2002. A numerical investigation of Lg geometrical spreading[J]. Bull Seismol Soc Am,92(8):3067–3079. doi: 10.1785/0120020046

    Zhao L F,Xie X B,Wang W M,Zhang J H,Yao Z X. 2010. Seismic Lg-wave Q tomography in and around Northeast China[J]. J Geophys Res,115(B8):B08307.

    Zhao L F,Xie X B,He J K,Tian X B,Yao Z X. 2013a. Crustal flow pattern beneath the Tibetan Plateau constrained by regional Lg-wave Q tomography[J]. Earth Planet Sci Lett,383:113–122. doi: 10.1016/j.jpgl.2013.09.038

    Zhao L F,Xie X B,Wang W M,Zhang J H,Yao Z X. 2013b. Crustal Lg attenuation within the North China Craton and its surrounding regions[J]. Geophys J Int,195(1):513–531. doi: 10.1093/gji/ggt235

    Zhao W L,Morgan W J. 1987. Injection of Indian crust into Tibetan lower crust:A two-dimensional finite element model study[J]. Tectonics,6(4):489–504. doi: 10.1029/TC006i004p00489

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