利用背景噪声格林函数交叉项成像研究台湾地区面波相速度结构
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摘要
基于我国台湾地区24个宽频带地震台记录到的长达18个月的三分量连续波形数据,采用交叉项互相关方法提取了瑞雷波的经验格林函数张量,进而反演获得了台湾地区6—22 s周期的瑞雷波相速度分布图像,较好地刻画了该地区的地壳速度结构。结果显示:短周期图像上的滨海平原、屏东平原等呈低速特征,西部丘陵、中央山脉和海岸山脉呈高速特征;低速区域随相速度周期的增大而逐渐东移;中长周期图像上,中央山脉南北部均呈低速且南侧的速度较北侧低,表明欧亚板块和菲律宾海板块碰撞后的物质从东北和西南两个方向被侧向挤出时南部可能较北部活跃;台中—南投地区在对应深度附近的高速异常,表明新生代时期的澎湖地台在南海北缘的拉张与碰撞演化过程中,保留了其相对稳定的性质。
Based on the three-component continuous waveform data recorded by the 24 broadband seismic stations in the Broadband Array in Taiwan for Seismology(BATS) from January2016 to June 2017,the empirical Green's function tensors of surface waves are extracted by the cross-term correlation method. Rayleigh wave phase velocity maps from the period 6 s to 22 s are subsequently derived from cross-terms of the Green's function tensors,which made good description of the crustal velocity structure in Taiwan region. Our results show that the Coastal plain and the Pingtung basin exhibit low-velocity characteristics,while the Western Foothills,Central Range and Coastal Range exhibit high-velocity characteristics in the short-period band.The low velocity zone shifts eastward gradually with period increasing. On the medium and long periods,velocities in southern and northern segments of Central Range are significantly low,indicating the northward and southward material extrusion related to the lithospheric collision between the Eurasian Plate and the Philippine Sea Plate. Besides,the velocities in the southern segment of the Central Rang are slightly lower than that of the northern segment,which may imply the more active southward extrusion. In addition,the high-velocity anomaly near the related depth in Taichung-Nantou area may indicate that the Penghu platform retains its relatively stable state since the Cenozoic Era during the extension and collision evolution of the northern margin of the South China Sea.
Based on the three-component continuous waveform data recorded by the 24 broadband seismic stations in the Broadband Array in Taiwan for Seismology(BATS) from January2016 to June 2017,the empirical Green's function tensors of surface waves are extracted by the cross-term correlation method. Rayleigh wave phase velocity maps from the period 6 s to 22 s are subsequently derived from cross-terms of the Green's function tensors,which made good description of the crustal velocity structure in Taiwan region. Our results show that the Coastal plain and the Pingtung basin exhibit low-velocity characteristics,while the Western Foothills,Central Range and Coastal Range exhibit high-velocity characteristics in the short-period band.The low velocity zone shifts eastward gradually with period increasing. On the medium and long periods,velocities in southern and northern segments of Central Range are significantly low,indicating the northward and southward material extrusion related to the lithospheric collision between the Eurasian Plate and the Philippine Sea Plate. Besides,the velocities in the southern segment of the Central Rang are slightly lower than that of the northern segment,which may imply the more active southward extrusion. In addition,the high-velocity anomaly near the related depth in Taichung-Nantou area may indicate that the Penghu platform retains its relatively stable state since the Cenozoic Era during the extension and collision evolution of the northern margin of the South China Sea.
引文
房立华,吴建平,王未来,王长在,杨婷.2013.华北地区勒夫波噪声层析成像研究[J].地球物理学报,56(7):2268-2279.Fang L H,Wu J P,Wang W L,Wang C Z,Yang T.2013.Love wave tomography from ambient seismic noise in North-China[J].Chinese Journal of Geophysics,56(7):2268-2279(in Chinese).
何玉梅,姚振兴.2002.中国台湾南部及其周边岛屿现今地壳形变的位错模型[J].地球物理学报,45(5):638-645.He Y M,Yao Z X.2002.Dislocation model for current crustal deformation in and around southern Taiwan,China[J].Chinese Journal of Geophysics,45(5):638-645(in Chinese).
李志伟,胥颐,郝天珧,徐亚.2009.台湾地区的壳幔P波速度和v P/v S波速比结构研究[J].中国科学:D辑,39(9):1191-1199.Li Z W,Xu Y,Hao T Y,Xu Y.2009.v P and v P/v S structures in the crust and upper mantle of the Taiwan region,China[J].Science in China:Series D,52(7):975-983.
龙小刚,朱守彪.2015.台湾碰撞带现今地壳变形场特征及其动力学成因的有限单元法模拟研究[J].地球物理学报,58(7):2350-2365.Long X G,Zhu S B.2015.Present-day crustal strain field in the Taiwan active collision zone and its geodynamic mechanisms:Insight from FEM simulations[J].Chinese Journal of Geophysics,58(7):2350-2365(in Chinese).
孙金龙,徐辉龙,曹敬贺.2011.台湾-吕宋会聚带的地壳运动特征及其动力学机制[J].地球物理学报,54(12):3016-3025.Sun J L,Xu H L,Cao J H.2011.Crustal movement and its dynamic mechanism of the Taiwan-Luzon convergent zone[J].Chinese Journal of Geophysics,54(12):3016-3025(in Chinese).
吴啸龙.2017.台湾岛及其邻近区域弧-陆碰撞带现今地壳形变特征研究[J].测绘学报,46(2):268.Wu X L.2017.Study on present-day crustal deformation in the arc-continent collision zone of Taiwan and adjacent area[J].Acta Geodaetica et Cartographica Sinica,46(2):268(in Chinese).
杨志高,张雪梅.2018.青藏高原东北缘噪声层析成像研究[J].地震学报,40(1):1-12.Yang Z G,Zhang X M.2018.Ambient noise Rayleigh wave tomography in the northeastern Tibetan Plateau[J].Acta Seismologica Sinica,40(1):1-12(in Chinese).
周龙泉,吉平.2012.台湾地区的随机噪音瑞利波层析成像研究[J].地球物理学进展,27(4):1350-1358.Zhou L Q,Ji P.2012.Ambient noise Rayleigh wave tomography across Taiwan[J].Progress in Geophysics,27(4):1350-1358(in Chinese).
胥颐,李志伟,郝天珧,刘建华,刘劲松.2007.南海东北部及其邻近地区的Pn波速度结构与各向异性[J].地球物理学报,50(5):1473-1479.Xu Y,Li Z W,Hao T Y,Liu J H,Liu J S.2007.Pn wave velocity and anisotropy in the northeastern South China Sea and adjacent region[J].Chinese Journal of Geophysics,50(5):1473-1479(in Chinese).
Bao X W,Sun X X,Xu M J,Eaton D W,Song X D,Wang L S,Ding Z F,Mi N,Li H,Yu D Y,Huang Z C,Wang P.2015.Two crustal low-velocity channels beneath SE Tibet revealed by joint inversion of Rayleigh wave dispersion and receiver functions[J].Earth Planet Sci Lett,415:16-24.
Barmin M P,Ritzwoller M H,Levshin A L.2001.A fast and reliable method for surface wave tomography[J].Pure Appl Geophys,158(8):1351-1375.
Bensen G D,Ritzwoller M H,Barmin M P,Levshin A L,Lin F,Moschetti M P,Shapiro N M,Yang Y J.2007.Processing seismic ambient noise data to obtain reliable broad-band surface wave dispersion measurements[J].Geophys J Int,169(3):1239-1260.
Bos A G,Spakman W,Nyst M C J.2003.Surface deformation and tectonic setting of Taiwan inferred from a GPS velocity field[J].J Geophys Res,108(B10):2458.
Calkins J A,Zandt G,Girardi J,Dueker K,Gehrels G E,Ducea M N.2010.Characterization of the crust of the Coast Mountains Batholith,British Columbia,from P to S converted seismic waves and petrologic modeling[J].Earth Planet Sci Lett,289(1/2):145-155.
Chen K X,Kuo-Chen H,Brown D,Li Q S,Ye Z,Liang W T,Wang C Y,Yao H J.2016.3D ambient noise tomography across the Taiwan strait:The structure of a magma-poor rifted margin[J].Tectonics,35(8):1782-1792.
Cheng W B,Chang C H.2016.Tomographic imaging of a seismic cluster in northern Taiwan and its implications for crustal fluid migration[J].J Geodynam,101:200-214.
Craig T J,Copley A,Jackson J.2014.A reassessment of outer-rise seismicity and its implications for the mechanics of oceanic lithosphere[J].Geophys J Int,197(1):63-89.
Davis D,Suppe J,Dahlen F A.1983.Mechanics of fold-and-thrust belts and accretionary wedges[J].J Geophys Res,88(B2):1153-1172.
Hall R,Ali J R,Anderson C D,Baker S J.1995.Origin and motion history of the Philippine Sea Plate[J].Tectonophysics,251(1/4):229-250.
Haney M M,Mikesell T D,van Wijk K,Nakahara H.2012.Extension of the spatial autocorrelation(SPAC)method to mixedcomponent correlations of surface waves[J].Geophys J Int,191(1):189-206.
Huang M H,Hu J C,Hsieh C S,Ching K E,Rau R J,Pathier E,Fruneau B,Deffontaines B.2006.A growing structure near the deformation front in SW Taiwan as deduced from SAR interferometry and geodetic observation[J].Geophys Res Lett,33(12):L12305.
Huang T Y,Gung Y,Liang W T,Chiao L Y,Teng L S.2012.Broad-band Rayleigh wave tomography of Taiwan and its implications on gravity anomalies[J].Geophys Res Lett,39(5):L05305.
Hwang C,Hsiao Y S,Shih H C,Yang M,Chen K H,Forsberg R,Olesen A V.2007.Geodetic and geophysical results from a Taiwan airborne gravity survey:Data reduction and accuracy assessment[J].J Geophys Res,112(B4):B04407.
Kuo-Chen H,Wu F T,Roecker S W.2012.Three-dimensional P velocity structures of the lithosphere beneath Taiwan from the analysis of TAIGER and related seismic data sets[J].J Geophys Res,117(B6):B06306.
Lallemand S,Font Y,Bijwaard H,Kao H.2001.New insights on 3-D plates interaction near Taiwan from tomography and tectonic implications[J].Tectonophysics,335(3/4):229-253.
Levshin A L,Ritzwoller M H.2001.Automated detection,extraction,and measurement of regional surface waves[J].Pure Appl Geophys,158(8):1531-1545.
Li Z W,Roecker S,Kim K,Xu Y,Hao T Y.2014.Moho depth variations in the Taiwan orogen from joint inversion of seismic arrival time and Bouguer gravity data[J].Tectonophysics,632:151-159.
Lin A T,Watts A B.2002.Origin of the West Taiwan basin by orogenic loading and flexure of a rifted continental margin[J].JGeophys Res,107(B9):2185.
Lin A T,Watts A B,Hesselbo S P.2003.Cenozoic stratigraphy and subsidence history of the South China Sea margin in the Taiwan region[J].Basin Res,15(4):453-478.
Lu C Y,Jeng F S,Chang K J,Jian W T.1998.Impact of basement high on the structure and kinematics of the western Taiwan thrust wedge:Insights from sandbox models[J].Terr Atmos Ocean Sci,9(3):533-550.
Rau R J,Wu F T.1995.Tomographic imaging of lithospheric structures under Taiwan[J].Earth Planet Sci Lett,133(3/4):517-532.
Roecker S W,Yeh Y H,Tsai Y B.1987.Three-dimensional P and S wave velocity structures beneath Taiwan:Deep structure beneath an arc-continent collision[J].J Geophys Res,92(B10):10547-10570.
Shaw C L.1996.Stratigraphic correlation and isopach maps of the western Taiwan basin[J].Terr Atmos Ocean Sci,7(3):333-360.
Teng L S.1996.Extensional collapse of the northern Taiwan mountain belt[J].Geology,24(10):949-952.
van Wijk K,Mikesell T D,Schulte-Pelkum V,Stachnik J.2011.Estimating the Rayleigh-wave impulse response between seismic stations with the cross terms of the Green tensor[J].Geophys Res Lett,38(16):L16301.
Wang H L,Zhu L P,Chen H W.2010.Moho depth variation in Taiwan from teleseismic receiver functions[J].J Asian Earth Sci,37(3):286-291.
Wang Z,Zhao D P,Wang J,Kao H.2006.Tomographic evidence for the Eurasian lithosphere subducting beneath south Taiwan[J].Geophys Res Lett,33(18):L18306.
Wu F T.1978.Recent tectonics of Taiwan[J].J Phys Earth,26(S):S265-S299.
Wu F T,Rau R J,Salzberg D.1997.Taiwan orogeny:Thin-skinned or lithospheric collision?[J].Tectonophysics,274(1/2/3):191-220.
Wu W N,Yen Y T,Hsu Y J,Wu Y M,Lin J Y,Hsu S K.2017.Spatial variation of seismogenic depths of crustal earthquakes in the Taiwan region:Implications for seismic hazard assessment[J].Tectonophysics,708:81-95.
Xu Z B,Mikesell T D.2017.On the reliability of direct Rayleigh-wave estimation from multicomponent cross-correlations[J].Geophys J Int,210(3):1388-1393.
Yen H Y,Hsieh H H.2010.A study on the compatibility of 3D seismic velocity structures with gravity data of Taiwan[J].Terr Atmos Ocean Sci,21(6):897-904.
You S H,Gung Y,Chiao L Y,Chen Y N,Lin C H,Liang W T,Chen Y L.2010.Multiscale ambient noise tomography of short-period Rayleigh waves across northern Taiwan[J].Bull Seismol Soc Am,100(6):3165-3173.
Yu S B,Chen H Y,Kuo L C.1997.Velocity field of GPS stations in the Taiwan area[J].Tectonophysics,247(1/2/3):41-59.
Zheng Y,Shen W S,Zhou L Q,Yang Y J,Xie Z J,Ritzwoller M H.2011.Crust and uppermost mantle beneath the North China Craton,northeastern China,and the Sea of Japan from ambient noise tomography[J].J Geophys Res,116(B12):B12312.
何玉梅,姚振兴.2002.中国台湾南部及其周边岛屿现今地壳形变的位错模型[J].地球物理学报,45(5):638-645.He Y M,Yao Z X.2002.Dislocation model for current crustal deformation in and around southern Taiwan,China[J].Chinese Journal of Geophysics,45(5):638-645(in Chinese).
李志伟,胥颐,郝天珧,徐亚.2009.台湾地区的壳幔P波速度和v P/v S波速比结构研究[J].中国科学:D辑,39(9):1191-1199.Li Z W,Xu Y,Hao T Y,Xu Y.2009.v P and v P/v S structures in the crust and upper mantle of the Taiwan region,China[J].Science in China:Series D,52(7):975-983.
龙小刚,朱守彪.2015.台湾碰撞带现今地壳变形场特征及其动力学成因的有限单元法模拟研究[J].地球物理学报,58(7):2350-2365.Long X G,Zhu S B.2015.Present-day crustal strain field in the Taiwan active collision zone and its geodynamic mechanisms:Insight from FEM simulations[J].Chinese Journal of Geophysics,58(7):2350-2365(in Chinese).
孙金龙,徐辉龙,曹敬贺.2011.台湾-吕宋会聚带的地壳运动特征及其动力学机制[J].地球物理学报,54(12):3016-3025.Sun J L,Xu H L,Cao J H.2011.Crustal movement and its dynamic mechanism of the Taiwan-Luzon convergent zone[J].Chinese Journal of Geophysics,54(12):3016-3025(in Chinese).
吴啸龙.2017.台湾岛及其邻近区域弧-陆碰撞带现今地壳形变特征研究[J].测绘学报,46(2):268.Wu X L.2017.Study on present-day crustal deformation in the arc-continent collision zone of Taiwan and adjacent area[J].Acta Geodaetica et Cartographica Sinica,46(2):268(in Chinese).
杨志高,张雪梅.2018.青藏高原东北缘噪声层析成像研究[J].地震学报,40(1):1-12.Yang Z G,Zhang X M.2018.Ambient noise Rayleigh wave tomography in the northeastern Tibetan Plateau[J].Acta Seismologica Sinica,40(1):1-12(in Chinese).
周龙泉,吉平.2012.台湾地区的随机噪音瑞利波层析成像研究[J].地球物理学进展,27(4):1350-1358.Zhou L Q,Ji P.2012.Ambient noise Rayleigh wave tomography across Taiwan[J].Progress in Geophysics,27(4):1350-1358(in Chinese).
胥颐,李志伟,郝天珧,刘建华,刘劲松.2007.南海东北部及其邻近地区的Pn波速度结构与各向异性[J].地球物理学报,50(5):1473-1479.Xu Y,Li Z W,Hao T Y,Liu J H,Liu J S.2007.Pn wave velocity and anisotropy in the northeastern South China Sea and adjacent region[J].Chinese Journal of Geophysics,50(5):1473-1479(in Chinese).
Bao X W,Sun X X,Xu M J,Eaton D W,Song X D,Wang L S,Ding Z F,Mi N,Li H,Yu D Y,Huang Z C,Wang P.2015.Two crustal low-velocity channels beneath SE Tibet revealed by joint inversion of Rayleigh wave dispersion and receiver functions[J].Earth Planet Sci Lett,415:16-24.
Barmin M P,Ritzwoller M H,Levshin A L.2001.A fast and reliable method for surface wave tomography[J].Pure Appl Geophys,158(8):1351-1375.
Bensen G D,Ritzwoller M H,Barmin M P,Levshin A L,Lin F,Moschetti M P,Shapiro N M,Yang Y J.2007.Processing seismic ambient noise data to obtain reliable broad-band surface wave dispersion measurements[J].Geophys J Int,169(3):1239-1260.
Bos A G,Spakman W,Nyst M C J.2003.Surface deformation and tectonic setting of Taiwan inferred from a GPS velocity field[J].J Geophys Res,108(B10):2458.
Calkins J A,Zandt G,Girardi J,Dueker K,Gehrels G E,Ducea M N.2010.Characterization of the crust of the Coast Mountains Batholith,British Columbia,from P to S converted seismic waves and petrologic modeling[J].Earth Planet Sci Lett,289(1/2):145-155.
Chen K X,Kuo-Chen H,Brown D,Li Q S,Ye Z,Liang W T,Wang C Y,Yao H J.2016.3D ambient noise tomography across the Taiwan strait:The structure of a magma-poor rifted margin[J].Tectonics,35(8):1782-1792.
Cheng W B,Chang C H.2016.Tomographic imaging of a seismic cluster in northern Taiwan and its implications for crustal fluid migration[J].J Geodynam,101:200-214.
Craig T J,Copley A,Jackson J.2014.A reassessment of outer-rise seismicity and its implications for the mechanics of oceanic lithosphere[J].Geophys J Int,197(1):63-89.
Davis D,Suppe J,Dahlen F A.1983.Mechanics of fold-and-thrust belts and accretionary wedges[J].J Geophys Res,88(B2):1153-1172.
Hall R,Ali J R,Anderson C D,Baker S J.1995.Origin and motion history of the Philippine Sea Plate[J].Tectonophysics,251(1/4):229-250.
Haney M M,Mikesell T D,van Wijk K,Nakahara H.2012.Extension of the spatial autocorrelation(SPAC)method to mixedcomponent correlations of surface waves[J].Geophys J Int,191(1):189-206.
Huang M H,Hu J C,Hsieh C S,Ching K E,Rau R J,Pathier E,Fruneau B,Deffontaines B.2006.A growing structure near the deformation front in SW Taiwan as deduced from SAR interferometry and geodetic observation[J].Geophys Res Lett,33(12):L12305.
Huang T Y,Gung Y,Liang W T,Chiao L Y,Teng L S.2012.Broad-band Rayleigh wave tomography of Taiwan and its implications on gravity anomalies[J].Geophys Res Lett,39(5):L05305.
Hwang C,Hsiao Y S,Shih H C,Yang M,Chen K H,Forsberg R,Olesen A V.2007.Geodetic and geophysical results from a Taiwan airborne gravity survey:Data reduction and accuracy assessment[J].J Geophys Res,112(B4):B04407.
Kuo-Chen H,Wu F T,Roecker S W.2012.Three-dimensional P velocity structures of the lithosphere beneath Taiwan from the analysis of TAIGER and related seismic data sets[J].J Geophys Res,117(B6):B06306.
Lallemand S,Font Y,Bijwaard H,Kao H.2001.New insights on 3-D plates interaction near Taiwan from tomography and tectonic implications[J].Tectonophysics,335(3/4):229-253.
Levshin A L,Ritzwoller M H.2001.Automated detection,extraction,and measurement of regional surface waves[J].Pure Appl Geophys,158(8):1531-1545.
Li Z W,Roecker S,Kim K,Xu Y,Hao T Y.2014.Moho depth variations in the Taiwan orogen from joint inversion of seismic arrival time and Bouguer gravity data[J].Tectonophysics,632:151-159.
Lin A T,Watts A B.2002.Origin of the West Taiwan basin by orogenic loading and flexure of a rifted continental margin[J].JGeophys Res,107(B9):2185.
Lin A T,Watts A B,Hesselbo S P.2003.Cenozoic stratigraphy and subsidence history of the South China Sea margin in the Taiwan region[J].Basin Res,15(4):453-478.
Lu C Y,Jeng F S,Chang K J,Jian W T.1998.Impact of basement high on the structure and kinematics of the western Taiwan thrust wedge:Insights from sandbox models[J].Terr Atmos Ocean Sci,9(3):533-550.
Rau R J,Wu F T.1995.Tomographic imaging of lithospheric structures under Taiwan[J].Earth Planet Sci Lett,133(3/4):517-532.
Roecker S W,Yeh Y H,Tsai Y B.1987.Three-dimensional P and S wave velocity structures beneath Taiwan:Deep structure beneath an arc-continent collision[J].J Geophys Res,92(B10):10547-10570.
Shaw C L.1996.Stratigraphic correlation and isopach maps of the western Taiwan basin[J].Terr Atmos Ocean Sci,7(3):333-360.
Teng L S.1996.Extensional collapse of the northern Taiwan mountain belt[J].Geology,24(10):949-952.
van Wijk K,Mikesell T D,Schulte-Pelkum V,Stachnik J.2011.Estimating the Rayleigh-wave impulse response between seismic stations with the cross terms of the Green tensor[J].Geophys Res Lett,38(16):L16301.
Wang H L,Zhu L P,Chen H W.2010.Moho depth variation in Taiwan from teleseismic receiver functions[J].J Asian Earth Sci,37(3):286-291.
Wang Z,Zhao D P,Wang J,Kao H.2006.Tomographic evidence for the Eurasian lithosphere subducting beneath south Taiwan[J].Geophys Res Lett,33(18):L18306.
Wu F T.1978.Recent tectonics of Taiwan[J].J Phys Earth,26(S):S265-S299.
Wu F T,Rau R J,Salzberg D.1997.Taiwan orogeny:Thin-skinned or lithospheric collision?[J].Tectonophysics,274(1/2/3):191-220.
Wu W N,Yen Y T,Hsu Y J,Wu Y M,Lin J Y,Hsu S K.2017.Spatial variation of seismogenic depths of crustal earthquakes in the Taiwan region:Implications for seismic hazard assessment[J].Tectonophysics,708:81-95.
Xu Z B,Mikesell T D.2017.On the reliability of direct Rayleigh-wave estimation from multicomponent cross-correlations[J].Geophys J Int,210(3):1388-1393.
Yen H Y,Hsieh H H.2010.A study on the compatibility of 3D seismic velocity structures with gravity data of Taiwan[J].Terr Atmos Ocean Sci,21(6):897-904.
You S H,Gung Y,Chiao L Y,Chen Y N,Lin C H,Liang W T,Chen Y L.2010.Multiscale ambient noise tomography of short-period Rayleigh waves across northern Taiwan[J].Bull Seismol Soc Am,100(6):3165-3173.
Yu S B,Chen H Y,Kuo L C.1997.Velocity field of GPS stations in the Taiwan area[J].Tectonophysics,247(1/2/3):41-59.
Zheng Y,Shen W S,Zhou L Q,Yang Y J,Xie Z J,Ritzwoller M H.2011.Crust and uppermost mantle beneath the North China Craton,northeastern China,and the Sea of Japan from ambient noise tomography[J].J Geophys Res,116(B12):B12312.