从震后形变探讨青藏高原下地壳黏滞系数
摘要
青藏高原下地壳黏滞系数究竟是多少,已成为深入定量研究中的突出问题,它的数值量级将极大地影响定量模拟的结果.为了获得青藏高原下地壳的黏滞系数,从3条途径对该参数进行了计算:一是基于对青藏高原深部温度状态改进了的估计,用流变定律和GPS求得的应变速率对高原北部下地壳黏滞系数重新进行了估算,获得的昆仑山地区中地壳等效黏滞系数为1020~1022Pa·s量级,下地壳等效黏滞系数在1019~1021Pa·s之间.二是用3种流变模型对2001年昆仑山MS8.1级地震震后跨断层GPS站点记录到的震后变形进行了模拟,得到的下地壳黏滞系数为1017Pa·s量级.三是用黏弹性模型对炉霍地震后的跨断层形变曲线进行了拟合,得到的下地壳黏滞系数为1019Pa·s量级.前人研究等效黏滞系数时忽视了等效黏滞系数与应变速率存在的非线性关系,本研究结果协调地解释了实验室实验、大地震后较短时期的变形和大地震后较长时间变形下,其等效黏滞系数存在差异的问题.
引文
1Royden L.Coupling and decoupling of crust and mantle in convergent orogens:implications for strain partitioning in the crust.J Geophys Res,1996,101:17679—17705
2Beaumont C,Jamieson R A,Nguyen M H,et al.Himalayan tectonics explained by extrusion of a low viscosity crustal channel coupled to focused surface denudation.Nature,2001,414:738—742
3Clark M K,Royden L H.Topographic ooze:building the eastern margin of Tibet by lower crustal flow.Geology,2000,28(8):703—706
4Hilley G E,Burgmann R,Zhang P Z,et al.Bayesian inference of plastosphere viscosities near the Kunlun Fault,northern Tibet.Geo-phys Res Lett,2005,32:L01302,doi:10.1029/2004GL021658
5Ryder I,Parsons B,Wright T J,et al,Post-seismic motion following the1997Manyi(Tibet)earthquake:InSAR observations and modeling.Geophys J Int,2007,169:1009—1027,doi:10.1111/j.1365—246X.2006.03312.x
6Shen Z K,Zeng Y,Wang M,et al.Postseismic deformation modeling of the2001Kokoxili earthquake,western China.Geophys Res Abs,2003,5:07840
7安美建,石耀霖.中国大陆地壳和上地幔三维温度场.中国科学D辑:地球科学,2007,37(6):736—745
8臧绍先,李昶,魏荣强.岩石圈流变机制的确定及影响岩石圈流变强度的因素.地球物理学进展,2002,17(1):50—60
9Zang S X,Wei R Q.Three-dimensional rheological structure of the lithosphere in the Ordos block and its adjacent area.Geophys J Int,2005,163:339—356
10高山,骆庭川,张本仁,等.中国东部地壳的结构和组成.中国科学D辑:地球科学,1999,29(3):204—213
11Carter N L,Tsenn M C.Flow properties of continental lithosphere.Tectonophysics,1987,136:27—63
12Hansen F D,Carter N L.Creep of selected crustal rocks at1000MPa.EOS,Trans Am Geophys Union,1982,63(18):437
13Wilks K R,Carter N L.Rheology of some continental lower crustal rocks.Tectonophysics,1990,182:57—77
14Zhu S B,Shi Y L.The contemporary tectonic strain rate field of continental China predicted from GPS measurements and its geody-namic implications.Pure Appl Geophys,2006,163:1477—1493
15Ranalli G.Rheology of the lithosphere in space and time.Orogeny Through Time.London:The Geological Society,1997.19—37
16任金卫,王敏.GPS观测的2001年昆仑山口西Ms8.1级地震地壳变形.第四纪研究,2005,25(1):33—44
17Wang R,Lorenzo-Martin F,Roth F.PSGRN/PSCMP—A new code for calculating co-and post-seismic deformation,geoid and gravity changes based on the viscoelastic-gravitational dislocation theory.Comput Geosci,2006,32(4):527—541
18Zhang C J,Shi Y L,Ma L,et al.Rheological model of post-seismic deformation of Kunlun Earthquake,Nov.14,2001,China.Geofisica Int,2007,46(3):145—154
19安美建,石耀霖.中国大陆岩石圈厚度分布研究.地学前缘,2006,13(3):23—30
20尤明庆,苏承东,杨圣奇.岩石动静态参数间关系的研究.焦作工学院学报(自然科学版),2002,21(6):413—419
21林邦慧,陈天长,薄晓红,等.鲜水河断裂带强震的破裂过程与地震活动.地震学报,1986,8(1):1—20
22闻学泽.四川鲜水河-安宁河-则木河断裂带的地震破裂分段特征.地震地质,2000,22(3):239—249
23王椿镛,Mooney W D,王溪莉,等.川滇地区地壳上地幔三维速度结构研究.地震学报,2002,24(1):1—16
24Wang Y.Heat flow pattern and lateral variations of lithoshpere strength in China mainland:constraints on acitve deformation.Phys Earth Planet Int,2001,126:121—146
25孙钧.岩石流变力学及其工程应用研究的若干进展.岩石力学与工程学报,2007,26(6):1081—1106
2Beaumont C,Jamieson R A,Nguyen M H,et al.Himalayan tectonics explained by extrusion of a low viscosity crustal channel coupled to focused surface denudation.Nature,2001,414:738—742
3Clark M K,Royden L H.Topographic ooze:building the eastern margin of Tibet by lower crustal flow.Geology,2000,28(8):703—706
4Hilley G E,Burgmann R,Zhang P Z,et al.Bayesian inference of plastosphere viscosities near the Kunlun Fault,northern Tibet.Geo-phys Res Lett,2005,32:L01302,doi:10.1029/2004GL021658
5Ryder I,Parsons B,Wright T J,et al,Post-seismic motion following the1997Manyi(Tibet)earthquake:InSAR observations and modeling.Geophys J Int,2007,169:1009—1027,doi:10.1111/j.1365—246X.2006.03312.x
6Shen Z K,Zeng Y,Wang M,et al.Postseismic deformation modeling of the2001Kokoxili earthquake,western China.Geophys Res Abs,2003,5:07840
7安美建,石耀霖.中国大陆地壳和上地幔三维温度场.中国科学D辑:地球科学,2007,37(6):736—745
8臧绍先,李昶,魏荣强.岩石圈流变机制的确定及影响岩石圈流变强度的因素.地球物理学进展,2002,17(1):50—60
9Zang S X,Wei R Q.Three-dimensional rheological structure of the lithosphere in the Ordos block and its adjacent area.Geophys J Int,2005,163:339—356
10高山,骆庭川,张本仁,等.中国东部地壳的结构和组成.中国科学D辑:地球科学,1999,29(3):204—213
11Carter N L,Tsenn M C.Flow properties of continental lithosphere.Tectonophysics,1987,136:27—63
12Hansen F D,Carter N L.Creep of selected crustal rocks at1000MPa.EOS,Trans Am Geophys Union,1982,63(18):437
13Wilks K R,Carter N L.Rheology of some continental lower crustal rocks.Tectonophysics,1990,182:57—77
14Zhu S B,Shi Y L.The contemporary tectonic strain rate field of continental China predicted from GPS measurements and its geody-namic implications.Pure Appl Geophys,2006,163:1477—1493
15Ranalli G.Rheology of the lithosphere in space and time.Orogeny Through Time.London:The Geological Society,1997.19—37
16任金卫,王敏.GPS观测的2001年昆仑山口西Ms8.1级地震地壳变形.第四纪研究,2005,25(1):33—44
17Wang R,Lorenzo-Martin F,Roth F.PSGRN/PSCMP—A new code for calculating co-and post-seismic deformation,geoid and gravity changes based on the viscoelastic-gravitational dislocation theory.Comput Geosci,2006,32(4):527—541
18Zhang C J,Shi Y L,Ma L,et al.Rheological model of post-seismic deformation of Kunlun Earthquake,Nov.14,2001,China.Geofisica Int,2007,46(3):145—154
19安美建,石耀霖.中国大陆岩石圈厚度分布研究.地学前缘,2006,13(3):23—30
20尤明庆,苏承东,杨圣奇.岩石动静态参数间关系的研究.焦作工学院学报(自然科学版),2002,21(6):413—419
21林邦慧,陈天长,薄晓红,等.鲜水河断裂带强震的破裂过程与地震活动.地震学报,1986,8(1):1—20
22闻学泽.四川鲜水河-安宁河-则木河断裂带的地震破裂分段特征.地震地质,2000,22(3):239—249
23王椿镛,Mooney W D,王溪莉,等.川滇地区地壳上地幔三维速度结构研究.地震学报,2002,24(1):1—16
24Wang Y.Heat flow pattern and lateral variations of lithoshpere strength in China mainland:constraints on acitve deformation.Phys Earth Planet Int,2001,126:121—146
25孙钧.岩石流变力学及其工程应用研究的若干进展.岩石力学与工程学报,2007,26(6):1081—1106
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心