利用面波方法研究欧亚大陆及周边海域岩石圈结构
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摘要
根据欧亚大陆及周边海域114个数字地震台站12 000多个长周期波形记录,采用面波频散反演方法,对欧亚大陆及周边海域(20°W～160°E,20°S～80°N)的地壳上地幔进行了高分辨率三维S波速度成像。结果表明,欧亚大陆及其周边海域岩石圈厚度由40～60km(大陆裂谷带)增厚至190～220km(克拉通地区),岩石圈速度变化范围为4.30～4.80km/s。直到400km深度,各个板块和地块的横向差异才逐渐减小。克拉通板块及地块的岩石圈巨厚且具有高速特征,软流圈很薄或不存在;显生宙造山带、边缘海等区域岩石圈较薄且速度较低,软流圈发育。海洋板块的显著特征是VS在岩石圈内异常高,而软流圈速度又异常低,有十分尖锐的速度突变。
This paper deals with the high resolution surface wave tomography in Eurasia and its surrounding seas(20°W～160°E,20°S～80°N).More than 12 000 long-period waveforms from about 2000 events(7.0≥M≥5.0) recorded at 114 digital seismic stations from CDSN,GDSN,GSN and GEOSCOPE network in Eurasia and its surrounding regions were used in this paper.The results show that in Eurasia and its surrounding seas,the lithosphere thickness is from 40～60 km(continental rift zone) to 190～220 km(Craton region),the lithosphere velocity range is 4.30～4.80 km/s.Until 400 km depth,the various differences between the horizontal plate and block gradually decrease.In precambrian craton and block,the lithosphere is very thick and high VS,the asthenosphere is very thin or non-existent;in marginal sea and Phanerozoic orogenic regional,lithosphere is thin and low VS,the asthenosphere is very large.Distinctive features of oceanic plates is uncommonly high VS in lithosphere,and abnormally low VS in asthenosphere,the rate of mutation is very sharp in velocity-depth curves.
This paper deals with the high resolution surface wave tomography in Eurasia and its surrounding seas(20°W～160°E,20°S～80°N).More than 12 000 long-period waveforms from about 2000 events(7.0≥M≥5.0) recorded at 114 digital seismic stations from CDSN,GDSN,GSN and GEOSCOPE network in Eurasia and its surrounding regions were used in this paper.The results show that in Eurasia and its surrounding seas,the lithosphere thickness is from 40～60 km(continental rift zone) to 190～220 km(Craton region),the lithosphere velocity range is 4.30～4.80 km/s.Until 400 km depth,the various differences between the horizontal plate and block gradually decrease.In precambrian craton and block,the lithosphere is very thick and high VS,the asthenosphere is very thin or non-existent;in marginal sea and Phanerozoic orogenic regional,lithosphere is thin and low VS,the asthenosphere is very large.Distinctive features of oceanic plates is uncommonly high VS in lithosphere,and abnormally low VS in asthenosphere,the rate of mutation is very sharp in velocity-depth curves.
引文
[1]Feng C C,Teng T L.Three-dimensional crust and upper mantle structure of the Eurasian Continent[J].J.Geophys.Res.,1983,88:2261-2273.
[2]宋仲和,陈国英,安昌强,等.中国大陆及其海域地壳—上地幔三维速度结构[J].中国科学(B),1993,23(2):180-188.
[3]冯锐,朱介寿,丁韫玉,等.利用地震面波研究中国地壳结构[J].地震学报,1981,3(4),335-350.
[4]周兵,朱介寿,秦建业.青藏高原及邻近区域S波三维速度结构[J].地球物理学报,1991,34(4):426-441.
[5]Ritzwoller M H,Levshin A L.Eurasian surface wave tomography:group velocities[J].J.Geophys.Res.,1998,103(B3):4839-4878.
[6]Maceira M,Taylor S R,Ammon C J,et al.High-resolution Rayleigh wave slowness tomography of central Asia[J].J.Geophys.Res.,2005,110,B06304,doi:10.1029/2004JB003429.
[7]Pasyanos M E.A variable resolution surface wave dispersion study of Eurasia,North Africa,and surrounding regions[J].J.Geophys.Res.,2005,110,B12301,doi:10.1029/2005JB003749.
[8]朱介寿.欧亚大陆及边缘海岩石圈的结构特性[J].地学前缘,2007,14(3):1-20.
[9]朱介寿,曹家敏,蔡学林,等.欧亚大陆及西太平洋边缘海岩石圈结构[J].地球科学进展,2004,19(3):387-392.
[10]朱介寿,曹家敏,蔡学林,等.东亚及西太平洋边缘海高分辨率面波层析成像[J].地球物理学报,2002,45(5):646-664.
[11]朱介寿,宣瑞卿,刘魁,等.用瑞利面波研究东亚及西太平洋地壳上地幔速度结构[J].物探化探计算技术,2005,27(3):185-192.
[12]朱介寿,曹家敏,蔡学林,等.中国及邻近陆域海域地球内部三维结构及动力学研究[J].地球科学进展,2003,18(4):497-503.
[13]K Priestley,E Debayle,D McKenzie,et al.Upper mantle structure of eastern Asia from multimode surface waveform tomography[J].J.Geophys.Res.,2006,111,B10304,doi:10.1029/2005JB004082.
[2]宋仲和,陈国英,安昌强,等.中国大陆及其海域地壳—上地幔三维速度结构[J].中国科学(B),1993,23(2):180-188.
[3]冯锐,朱介寿,丁韫玉,等.利用地震面波研究中国地壳结构[J].地震学报,1981,3(4),335-350.
[4]周兵,朱介寿,秦建业.青藏高原及邻近区域S波三维速度结构[J].地球物理学报,1991,34(4):426-441.
[5]Ritzwoller M H,Levshin A L.Eurasian surface wave tomography:group velocities[J].J.Geophys.Res.,1998,103(B3):4839-4878.
[6]Maceira M,Taylor S R,Ammon C J,et al.High-resolution Rayleigh wave slowness tomography of central Asia[J].J.Geophys.Res.,2005,110,B06304,doi:10.1029/2004JB003429.
[7]Pasyanos M E.A variable resolution surface wave dispersion study of Eurasia,North Africa,and surrounding regions[J].J.Geophys.Res.,2005,110,B12301,doi:10.1029/2005JB003749.
[8]朱介寿.欧亚大陆及边缘海岩石圈的结构特性[J].地学前缘,2007,14(3):1-20.
[9]朱介寿,曹家敏,蔡学林,等.欧亚大陆及西太平洋边缘海岩石圈结构[J].地球科学进展,2004,19(3):387-392.
[10]朱介寿,曹家敏,蔡学林,等.东亚及西太平洋边缘海高分辨率面波层析成像[J].地球物理学报,2002,45(5):646-664.
[11]朱介寿,宣瑞卿,刘魁,等.用瑞利面波研究东亚及西太平洋地壳上地幔速度结构[J].物探化探计算技术,2005,27(3):185-192.
[12]朱介寿,曹家敏,蔡学林,等.中国及邻近陆域海域地球内部三维结构及动力学研究[J].地球科学进展,2003,18(4):497-503.
[13]K Priestley,E Debayle,D McKenzie,et al.Upper mantle structure of eastern Asia from multimode surface waveform tomography[J].J.Geophys.Res.,2006,111,B10304,doi:10.1029/2005JB004082.
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