中国及邻区大地水准面异常的场源深度探讨
|
摘要
利用中国及邻区地形、地震层析成像、沉积层底面、Moho面及岩石层底面资料 ,正演计算出中国及邻区岩石圈大地水准面异常 ;再从全阶大地水准面异常中扣除正演模拟得到的岩石圈大地水准面异常与不同阶次波段的大地水准面进行比较 ,寻求表示中国及邻区地幔物质不均匀的大地水准面异常的最佳阶次为 2— 6 0阶 .结果表明 ,对应于岩石圈的大地水准面异常的重力位球谐函数阶数为 6 1— 72 0阶 ;下地幔重力位球谐函数阶数为 2— 6阶 ;而 7—6 0阶重力位球谐函数则表示中国及邻近区域上地幔大地水准面异常 .
The paper simulates the middle-short wavelength geoid anomaly in China and its adjacent regions by using the results of tectonics and distribution of density, detected by of tomography, seismic sounding and telluric electromagnetic sounding method. The geoid anomaly caused by the Moho interface is similar to the geoid anomaly caused by topography, but the undulation range is much less than later. Deducting the lithosphere simulated geoid anomaly from the geoid, we can obtain the mantle geoid anomaly. Comparing the mantle geoid anomaly to the geoid calculated by different order geo-potential model, we find that order 2_60 is best to describe the mantle geoid anomaly. The results show that the best order of the geo-potential is 61_720 for the lithosphere, 7_60 for the upper mantle, and 2_6 for the lower mantle.
The paper simulates the middle-short wavelength geoid anomaly in China and its adjacent regions by using the results of tectonics and distribution of density, detected by of tomography, seismic sounding and telluric electromagnetic sounding method. The geoid anomaly caused by the Moho interface is similar to the geoid anomaly caused by topography, but the undulation range is much less than later. Deducting the lithosphere simulated geoid anomaly from the geoid, we can obtain the mantle geoid anomaly. Comparing the mantle geoid anomaly to the geoid calculated by different order geo-potential model, we find that order 2_60 is best to describe the mantle geoid anomaly. The results show that the best order of the geo-potential is 61_720 for the lithosphere, 7_60 for the upper mantle, and 2_6 for the lower mantle.
引文
[1] Dziewonski,A .M .,Hager,B .H .andO’Connell,R .J.LargeScaleheterogeneitiesinLowerMantle.J.Geophys.Res.,1977,82(B1):239—255.
[2] Richards,M .A ,Hager,B .H .GeoidAnomalyinadynamicearth,J .Geophys.Res.,1984,89(B7):6003—6015.
[3] Biwin.C .Depthofprincipalmassanomaliescontributingtoearth’sgeoidundulationsandgravityanomalies.MarineGeodesy,1983,7(1):61—101.
[4] 朱介寿,曹家敏,李显贵等.中国及邻区地球三维结构初始模型的建立.地球物理学报,1997,40(5):627—648.ZHUJieShou,CAOJiaMin,LIXianGui,etal.Establishofpreliminaryearthmodelofthree dimensionalstructureinChinaanditssurroundingarea.ChineseJ.Geophys.(ActaGeophysicaSinica),1997,40(5):627—648.
[5] 许厚泽,陆仲连著.中国地球重力场与大地水准面.北京:解放军出版社,1997.HSUHouTze,LUZhongLian,EarthgravityandGeoidinChina(inChinese).Beijing:PublishingHouseofPeopleLiberationArmy,1997.
[6] Dziewonski,A .M .MappingtheLowerMantle:DeterminationofLateralHeterogeneityinPVelocityuptoDegreeandOrder6.J.Geophys.Res.,1984,89(B7):5929—5952.
[7] 冯 锐,严惠芬,张若水.三维位场的快速反演方法及程序设计.地质学报,1986,4(3):390—403.FENGRui,YANHuiFen,ZHANGRuoShui.Therapidinversionof3Dpotential fieldandprogramdesign.ActaGeologicaSinica(inChinese),1986,4(3):390—430.
[8] 陆 洋,许厚泽.720阶高分辨率重力场模型IGG97L研究.地壳形变与地震,1998,18(Suppl.):1—7.LUYang,HSUHouTze.Thestudyofhigh resolutionIGG97gravitymodelorderof720.CrustalDeformationandEarthquake(inChinese),1998,18(Suppl.):1—7.
[9] Hager,B .H .Subductedslabsandthegeoid:ConstrainsonMantleRheologyandFlow.J.Geophys.Res.,1984,89(B7):6016—6031.
[10] Hager,B .H .,Richards,M .A .Long wavelengthinEarth’sgeoid:physicalmodelsanddynamicalimplications.PhilTrans.R .Soc.Lond.,1989,A(328):309—327.
[11] 李 立.中国大陆地壳上地幔电性特征.地球物理学报,1996,39(Suppl.):130—140.LILi.ThegeoelectricalcharacteristicofcrustanduppermantleinthecontinentalregionofChina.ChineseJ .Geophys.(ActaGeophysicaSinica)1996,39(Suppl.):130—140.
[12] 张赤军,方 剑.西藏与南亚地区大地水准面的场源及其动力效应初探.地球物理学报,1996,39(Suppl.):114—120.ZHANGChiJun,FANGJian.PreliminarystudyofGeoidsourcesanditsdynamicaleffectinTibetandSouthAsiaregion.Chi neseJ.Geophys(ActaGeophysicaSinica),1996,39(Suppl.):114—120.
[2] Richards,M .A ,Hager,B .H .GeoidAnomalyinadynamicearth,J .Geophys.Res.,1984,89(B7):6003—6015.
[3] Biwin.C .Depthofprincipalmassanomaliescontributingtoearth’sgeoidundulationsandgravityanomalies.MarineGeodesy,1983,7(1):61—101.
[4] 朱介寿,曹家敏,李显贵等.中国及邻区地球三维结构初始模型的建立.地球物理学报,1997,40(5):627—648.ZHUJieShou,CAOJiaMin,LIXianGui,etal.Establishofpreliminaryearthmodelofthree dimensionalstructureinChinaanditssurroundingarea.ChineseJ.Geophys.(ActaGeophysicaSinica),1997,40(5):627—648.
[5] 许厚泽,陆仲连著.中国地球重力场与大地水准面.北京:解放军出版社,1997.HSUHouTze,LUZhongLian,EarthgravityandGeoidinChina(inChinese).Beijing:PublishingHouseofPeopleLiberationArmy,1997.
[6] Dziewonski,A .M .MappingtheLowerMantle:DeterminationofLateralHeterogeneityinPVelocityuptoDegreeandOrder6.J.Geophys.Res.,1984,89(B7):5929—5952.
[7] 冯 锐,严惠芬,张若水.三维位场的快速反演方法及程序设计.地质学报,1986,4(3):390—403.FENGRui,YANHuiFen,ZHANGRuoShui.Therapidinversionof3Dpotential fieldandprogramdesign.ActaGeologicaSinica(inChinese),1986,4(3):390—430.
[8] 陆 洋,许厚泽.720阶高分辨率重力场模型IGG97L研究.地壳形变与地震,1998,18(Suppl.):1—7.LUYang,HSUHouTze.Thestudyofhigh resolutionIGG97gravitymodelorderof720.CrustalDeformationandEarthquake(inChinese),1998,18(Suppl.):1—7.
[9] Hager,B .H .Subductedslabsandthegeoid:ConstrainsonMantleRheologyandFlow.J.Geophys.Res.,1984,89(B7):6016—6031.
[10] Hager,B .H .,Richards,M .A .Long wavelengthinEarth’sgeoid:physicalmodelsanddynamicalimplications.PhilTrans.R .Soc.Lond.,1989,A(328):309—327.
[11] 李 立.中国大陆地壳上地幔电性特征.地球物理学报,1996,39(Suppl.):130—140.LILi.ThegeoelectricalcharacteristicofcrustanduppermantleinthecontinentalregionofChina.ChineseJ .Geophys.(ActaGeophysicaSinica)1996,39(Suppl.):130—140.
[12] 张赤军,方 剑.西藏与南亚地区大地水准面的场源及其动力效应初探.地球物理学报,1996,39(Suppl.):114—120.ZHANGChiJun,FANGJian.PreliminarystudyofGeoidsourcesanditsdynamicaleffectinTibetandSouthAsiaregion.Chi neseJ.Geophys(ActaGeophysicaSinica),1996,39(Suppl.):114—120.
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