丽江7.0级地震前后地壳密度动态变化三维反演
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摘要
利用滇西实验场1994—1996年6期重复重力观测数据,经平差处理得到重力场差分动态变化,运用块体生长模式和遗传反演方法反演了该区地下物质密度的变化。结果表明:该区地下物质密度变化图像基本反映了丽江7.0级地震前后震中南部区域地下物质密度动态演化过程;近震中区地震前后密度变化趋势为减小-加速减小-减速减小-发震-增大-加速增大;震源区南部地震前后密度变化经历了相对稳定-增大-减小-加速减小-发震-增大的过程,证实了震前存在扩容机制。
The repeated gravity data of western Yunnan in 6 terms from 1994 to 1996 were used to calculate the dynamic change of gravitational differentiation by means of adjustment.The density change images of underground materials were obtained with 3D inversion combining the model of body growing and genetic algorithm.The results show that the regional density change images basically reflect the dynamic evolution process of medium density before and after the Lijiang Ms 7.0 earthquake in the south central region of epicenter;decreasing-accelerated decreasing-decelerated decreasing-earthquake-increasing-accelerated increasing is the trend of density change before and after the earthquake in the region of epicenter and relative stabilization-increasing-decreasing-accelerated decreasing-earthquake-increasing is the progress of density change before and after the earthquake in the southern of epicenter region,it proves that there is the mechanism of volumetric dilatancy before earthquake.
The repeated gravity data of western Yunnan in 6 terms from 1994 to 1996 were used to calculate the dynamic change of gravitational differentiation by means of adjustment.The density change images of underground materials were obtained with 3D inversion combining the model of body growing and genetic algorithm.The results show that the regional density change images basically reflect the dynamic evolution process of medium density before and after the Lijiang Ms 7.0 earthquake in the south central region of epicenter;decreasing-accelerated decreasing-decelerated decreasing-earthquake-increasing-accelerated increasing is the trend of density change before and after the earthquake in the region of epicenter and relative stabilization-increasing-decreasing-accelerated decreasing-earthquake-increasing is the progress of density change before and after the earthquake in the southern of epicenter region,it proves that there is the mechanism of volumetric dilatancy before earthquake.
引文
1申重阳,李辉.研究现今地壳运动和强震机理的一种方法[J].地球物理学进展,2007,22(1):49-56.(Shen Chongyang and Li Hui.A method of analyzing the present crustal movement and the mechanism of strong shocks[J].Progress in geophysics,2007,22(1):49-56)
2Walsh J B.An analysis of local changes in gravity due to de-formation[J].Pure App1.Geophys.,1975,113:97-106.
3Walsh J B and Rice J R.Local changes in gravity resulting from deformation[J].J.Geophy.Res.,1979,84:165-170.
4陈运泰,顾浩鼎,卢造勋.1975年海城地震与1976年唐山地震前后的重力变化[J].地震学报,1980,2(1):21-31.(Chen Yuntai,Gu Haoding and Lu Zaoxun.Variation of gravity before and after the Haicheng earthquake,1975and the Tangshan earthquake,1976[J].Acta Seismologica Sini-ca,1980,2(1):21-31)
5申重阳,等.福建中部和东南沿海地壳内部密度变化分布特征的研究[J].地壳形变与地震,2000,20(2):50-55.(Shen Chongyang,et al.Study on distribution character-istics of crustal density change in middle and southeastern coast of Fujian[J].Crustal deformation and earthquate,2000,20(2):50-55)
6申重阳,吴云,甘家思.从地壳运动角度分析大陆强震机理的一种物理方法[J].中国地震,2001,17(1),70-81.(Shen Chongyang,Wu Yun and Gan Jiasi.A physical method of analyzing the mechanism of continental strong shocks from crustal movement,Earthquake Research in Chi-na,2001,15(3):282-297)
7申重阳,等.华北地区地壳密度变化特征的初步研究[J].大地测量与地球动力学,2003,23(1):29-34.(Shen Chongyang,et al.Characteristics of crustal density change in north China[J].Journal of geodesy and geodynamics,2003,23(1):29-34)
8玄松柏,等.地下密度变化三维反演的遗传算法研究[J].大地测量与地球动力学,2008,28(1):36-40.(Xuan Songbai,et al.On3-D inversion of density change under-ground with Genetic Algorithm[J].Journal of geodesy and geodynamics,2008,28(1):36-40)
9Antonio G,et al.Gravity inversion by means of growing bodies[J].Geophysics,2000,65(1):95-101.
10石耀霖,金文.面波频散反演地球内部构造的遗传算法[J].地球物理学报,1995,38(2):189-198.(Shi Yaolinand Jin Wen.Genetic algorithms inversion of lithospheric structure from surface wave dispersion[J].Acta Geophysi-ca Sinica,1995,38(2):189-198)
11Montesions F G,.Arnoso Ja and Vieira R.Using a genetic algorithm for3-D inversion of gravity data in Fuerteventura(Canary Islands)[J].Int.J.Sci.(Geol Rundsch),2005,94:301-316.
12柯小平,等.三维密度分布的遗传算法反演[J].大地测量与地球动力学,2009,29(1):41-45.(Ke Xiaoping,et al.3D density inversion with genetic algorithm[J].Journal of Geodesy and Geodynamics,2009,29(1):41-45)
13Pick M,et al.Theory of Earth’s gravity field[M].Elservi-er Science Publ.Co..1973.
14王石任,等.滇西试验场区三维重力反演研究[J].地壳形变与地震,1994,14(1):1-10.(Wang Shiren,et al.Three Dimensional Inversion of Gravity Anomalies in the Western Yunnan[J].Crustal Deformation and Earthquake,1994,14(1):1-10)
15白志明.深地震测深剖面的层析成像研究及其应用[D].中国地震局地球物理研究所,2002.(Bai Zhiming.Deep seismic sounding tomography:Research and Applica-tions[D].Institute of Geophysics,CEA,2002)
16白志明,王椿镛.云南地区上部地壳结构和地震构造环境的层析成像研究[J].地震学报,2003,25(2),117-127.(Bai Zhiming and Wang Chunyong.Tomographic investigation of the upper crustal structure and seismotec-tonic environments in Yunnan province[J].Acta Seis-mologica Sinica,2003,25(2),117-127)
17李辉,等.滇西地区重力场动态变化计算[J].地壳形变与地震,2000,20(1),60-66.(Li Hui,et al.Computation on dynamic gravity changes in the western area of Yunnan province[J].Crustal deformation and earthquake,2000,20(1),60-66)
18王永安,刘强,王世芹.丽江7.0级地震前跨断层形变累积率的变化特征[J].地震研究,2004,27(1):61-65.(Wang Yong’an,Liu Qiang and Wang Shiqin.Variation characteristics of cumulative Percentage of cross-fault de-formation beforeMs7.0Lijiang earthquake[J].Journal of Seismoidgical Research,2004,27(1):61-65)
19谢富仁,刘光旭,梁海庆.滇西北及邻区现代构造应力场[J].地震地质,1994,16(4):329-338.(Xie Furen,Liu Guangxu and Liang Haiqing.Recent tectonic stress field in northwest Yunan province and its adjacent areas[J].Seis-mology and Geology,1994,16(4):329-338)
20申重阳,李辉,付广裕,丽江7.0级地震重力前兆模式研究[J].地震学报,2003,25(2):163-171.(Shen Chongy-ang,Li Hui and Fu Guangyu.Study on a gravity precursor mode of theMs7.0Lijiang earthquake[J].Acta Seismolog-ical Sinica,2003,16(2):175-184)
2Walsh J B.An analysis of local changes in gravity due to de-formation[J].Pure App1.Geophys.,1975,113:97-106.
3Walsh J B and Rice J R.Local changes in gravity resulting from deformation[J].J.Geophy.Res.,1979,84:165-170.
4陈运泰,顾浩鼎,卢造勋.1975年海城地震与1976年唐山地震前后的重力变化[J].地震学报,1980,2(1):21-31.(Chen Yuntai,Gu Haoding and Lu Zaoxun.Variation of gravity before and after the Haicheng earthquake,1975and the Tangshan earthquake,1976[J].Acta Seismologica Sini-ca,1980,2(1):21-31)
5申重阳,等.福建中部和东南沿海地壳内部密度变化分布特征的研究[J].地壳形变与地震,2000,20(2):50-55.(Shen Chongyang,et al.Study on distribution character-istics of crustal density change in middle and southeastern coast of Fujian[J].Crustal deformation and earthquate,2000,20(2):50-55)
6申重阳,吴云,甘家思.从地壳运动角度分析大陆强震机理的一种物理方法[J].中国地震,2001,17(1),70-81.(Shen Chongyang,Wu Yun and Gan Jiasi.A physical method of analyzing the mechanism of continental strong shocks from crustal movement,Earthquake Research in Chi-na,2001,15(3):282-297)
7申重阳,等.华北地区地壳密度变化特征的初步研究[J].大地测量与地球动力学,2003,23(1):29-34.(Shen Chongyang,et al.Characteristics of crustal density change in north China[J].Journal of geodesy and geodynamics,2003,23(1):29-34)
8玄松柏,等.地下密度变化三维反演的遗传算法研究[J].大地测量与地球动力学,2008,28(1):36-40.(Xuan Songbai,et al.On3-D inversion of density change under-ground with Genetic Algorithm[J].Journal of geodesy and geodynamics,2008,28(1):36-40)
9Antonio G,et al.Gravity inversion by means of growing bodies[J].Geophysics,2000,65(1):95-101.
10石耀霖,金文.面波频散反演地球内部构造的遗传算法[J].地球物理学报,1995,38(2):189-198.(Shi Yaolinand Jin Wen.Genetic algorithms inversion of lithospheric structure from surface wave dispersion[J].Acta Geophysi-ca Sinica,1995,38(2):189-198)
11Montesions F G,.Arnoso Ja and Vieira R.Using a genetic algorithm for3-D inversion of gravity data in Fuerteventura(Canary Islands)[J].Int.J.Sci.(Geol Rundsch),2005,94:301-316.
12柯小平,等.三维密度分布的遗传算法反演[J].大地测量与地球动力学,2009,29(1):41-45.(Ke Xiaoping,et al.3D density inversion with genetic algorithm[J].Journal of Geodesy and Geodynamics,2009,29(1):41-45)
13Pick M,et al.Theory of Earth’s gravity field[M].Elservi-er Science Publ.Co..1973.
14王石任,等.滇西试验场区三维重力反演研究[J].地壳形变与地震,1994,14(1):1-10.(Wang Shiren,et al.Three Dimensional Inversion of Gravity Anomalies in the Western Yunnan[J].Crustal Deformation and Earthquake,1994,14(1):1-10)
15白志明.深地震测深剖面的层析成像研究及其应用[D].中国地震局地球物理研究所,2002.(Bai Zhiming.Deep seismic sounding tomography:Research and Applica-tions[D].Institute of Geophysics,CEA,2002)
16白志明,王椿镛.云南地区上部地壳结构和地震构造环境的层析成像研究[J].地震学报,2003,25(2),117-127.(Bai Zhiming and Wang Chunyong.Tomographic investigation of the upper crustal structure and seismotec-tonic environments in Yunnan province[J].Acta Seis-mologica Sinica,2003,25(2),117-127)
17李辉,等.滇西地区重力场动态变化计算[J].地壳形变与地震,2000,20(1),60-66.(Li Hui,et al.Computation on dynamic gravity changes in the western area of Yunnan province[J].Crustal deformation and earthquake,2000,20(1),60-66)
18王永安,刘强,王世芹.丽江7.0级地震前跨断层形变累积率的变化特征[J].地震研究,2004,27(1):61-65.(Wang Yong’an,Liu Qiang and Wang Shiqin.Variation characteristics of cumulative Percentage of cross-fault de-formation beforeMs7.0Lijiang earthquake[J].Journal of Seismoidgical Research,2004,27(1):61-65)
19谢富仁,刘光旭,梁海庆.滇西北及邻区现代构造应力场[J].地震地质,1994,16(4):329-338.(Xie Furen,Liu Guangxu and Liang Haiqing.Recent tectonic stress field in northwest Yunan province and its adjacent areas[J].Seis-mology and Geology,1994,16(4):329-338)
20申重阳,李辉,付广裕,丽江7.0级地震重力前兆模式研究[J].地震学报,2003,25(2):163-171.(Shen Chongy-ang,Li Hui and Fu Guangyu.Study on a gravity precursor mode of theMs7.0Lijiang earthquake[J].Acta Seismolog-ical Sinica,2003,16(2):175-184)
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