利用超导重力数据探测内核超速旋转的研究
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摘要
内核存在约(0.27°~0.53°)/a的超速旋转,由此导致的全球年平均重力变化强度约为0.08~0.16μGal(0.8~1.6 nms-2)。除地震数据外,时变重力数据有可能成为探测内核超速旋转速率的重要信息源。对武汉九峰台站超导重力仪观测数据进行了潮汐改正、大气负荷改正、极移改正和日长变化改正,得到了经过各项改正后的时变重力信号;采用小波分析方法对上述时变重力信号进行了处理分析,得到了可供参考的结果;针对目前利用超导重力仪数据探测内核超速旋转所存在的困难提出了几个解决方案和建议。
The inner core super rotation(ICSR) rate is 0.27°~0.53°/a,which gives rise to the annual average variation intensity about 0.08~0.16 μGal.Besides seismic data,temporary gravity data might become an important information source for detecting(ICSR).The influences caused by the tide,air pressure,polar motion and variation of the length of day,are drawn out from the gravity data recorded by the superconducting gravimeter(SG) at Jiufeng Station,Wuhan;and corrected temporary gravity signals are obtained.These temporary gravity signals are further analyzed by wavelet approach;and some valuble results are drawn out.Concerning the difficulties existed in detecting ICSR using SG data,some comments and proposals are provided.
The inner core super rotation(ICSR) rate is 0.27°~0.53°/a,which gives rise to the annual average variation intensity about 0.08~0.16 μGal.Besides seismic data,temporary gravity data might become an important information source for detecting(ICSR).The influences caused by the tide,air pressure,polar motion and variation of the length of day,are drawn out from the gravity data recorded by the superconducting gravimeter(SG) at Jiufeng Station,Wuhan;and corrected temporary gravity signals are obtained.These temporary gravity signals are further analyzed by wavelet approach;and some valuble results are drawn out.Concerning the difficulties existed in detecting ICSR using SG data,some comments and proposals are provided.
引文
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[6]陈巍.利用GOCE数据探测核幔差异旋转的可能性[D].武汉:武汉大学,武汉,2006
[7]陈晓东.武汉九峰台超导重力仪固体潮观测资料的预处理和分析结果[D].武汉:中国科学院测量与地球物理研究所,2003
[8]孙和平,陈晓东,许厚泽,等.GWR超导重力仪潮汐观测标定因子的精密测定[J].地震学报,2001,23(6):651-658
[9]陈晓东,孙和平.一种新的重力潮汐数据预处理和分析方法[J].大地测量与地球动力学,2002,22(3):83-87
[10]刘琳.核幔差异旋转对地球重力场的影响[D].武汉:武汉大学,2005
[11]罗少聪,孙和平.大气压力变化对武汉台站重力场观测的影响[J].测绘学报,2000,29:5-79
[12]孙和平,许厚泽,陶国祥,等.用超导重力仪观测数据精密测定地球潮汐常数[J].地壳形变与地震,1997,17:17-25
[13]徐建桥,孙和平,罗少聪.武汉基准台重力合成潮信号确定[J].地壳形变与地震,1999,19(3):26-31
[14]孙和平.大气重力格林函数[J].科学通报,1997,42:1 640-1 646
[15]Shearer P M.Introduction to Seismology[M].Cambridge:Cambridge University Press,2000
[16]Vanicek P.Approxi mate Spectral Analysis byLeast-squares Fit[J].Astroph Space Sci,1969,4:387-391
[17]Lomb N.Least-squares Frequency Analysis of Une-qually Spaced Data.Astrophys[J].Space Sci,1976,39:447-462
[18]Omerbshich M.A Gauss-Vanicek Spectral Analysisof the Sepkoski Compendium:no New18 life Cycles[J].Computing in Science and Engineering,2006,8:26-30
[19]徐建桥,周江存,罗少聪,孙和平.武汉台重力长期变化特征研究[J].科学通报,2008,53(5):583-588
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