地震研究

介绍了利用GRACE卫星数据计算和分析重力场变化的方法。以EIGEN-GRACE02S重力场模型为背景,对高斯平滑处理前后中国大陆月重力场的变化作了比较,认为取平均半径为666 km作高斯平滑,能够得到合理的重力变化结果。以3个月时间尺度计算了2008年汶川地震前后中国大陆的重力场变化,将结果与2006年和2007年相同时间尺度的变化结果进行比较,发现三者相符合,并且同震重力的负变化可用地壳膨胀模型理论来解释。

The method of calculating and analyzing the variation of gravity field with the GRACE satellite data is introduced.Taking the EIGEN-GRACE02S as a reference,we compare the monthly variation of the gravity field in Chinese mainland before the Gaussian Smoothing with the one after the Gaussian Smoothing.The reasonable variation of the gravity field can be obtained by Gaussian Smoothing when taking 666 km as the average radius.We calculate the variation of gravity field in Chinese mainland before and after the Wenchuan M_S8.0 earthquake in 2008.By three-month scale we compare the gravity field with the ones in 2006 and in 2007 and find that the three variation in three different years are accordant with each other.The negative coseismic gravity changes can be interpreted by the expansion of the Earth's crust model.

引言
1 GRACE卫星监测的重力变化计算
2 汶川地震前后重力场变化
3 结语

图1 滤波前(a)和滤波后(b)的重力变化(单位:10-8ms-2)<br/>Fig.1 Variation of gravitational field before GAUSS smoothing(a)and after GAUSS smoothing(b)(unit:10-8ms-2

图1 滤波前(a)和滤波后(b)的重力变化(单位:10-8ms-2)
Fig.1 Variation of gravitational field before GAUSS smoothing(a)and after GAUSS smoothing(b)(unit:10-8ms-2

图2 2006(a)、2007(b)和2008(c)5月、6月、7月3个月尺度的重力变化(单位:10-8ms-2)<br/>Fig.2 Variation of gravitational field of China by three-month scale in 2006(a),2007(b)and 2008(c)(unit:10-8ms-2)

图2 2006(a)、2007(b)和2008(c)5月、6月、7月3个月尺度的重力变化(单位:10-8ms-2)
Fig.2 Variation of gravitational field of China by three-month scale in 2006(a),2007(b)and 2008(c)(unit:10-8ms-2)

图3 2008年1月～6月成都和长春地区的重力变化(单位:10-8 ms-2)<br/>Fig.3 Variation of gravitational field of Chengdu and Changchun from January to June in 2008 (unit:10-8ms-2)

图3 2008年1月～6月成都和长春地区的重力变化(单位:10-8 ms-2)
Fig.3 Variation of gravitational field of Chengdu and Changchun from January to June in 2008 (unit:10-8ms-2)

付虹,李永莉,赵小艳,等.2008.云南M≥5地震震前异常的统计特征[J].地震研究,31(4):335-339.
郭俊义.1994.物理大地测量学基础[M].武汉:武汉测绘科技大学出版社.
罗志才.1996.利用卫星重力梯度数据确定地球重力场的理论和方法[D].武汉:武汉测绘科技大学.
孙文科.2008.地震火山活动产生重力变化的理论与观测研究的进展及现状[J].大地测量与地球动力学,28(4):44-53.
滕吉文,白登海,杨辉,等.2008.2008年汶川MS8.0地震发生的深层过程和动力学响应[J].地球物理学报,51(5):1385-1402.
王丹,李辉,申重阳,等.2005.地面重力时空变化向卫星高度的解析延拓[J].大地测量与地球动力学,25(2):69-74.
张培震,徐锡伟,闻学泽,等.2008.2008年汶川8.0级地震发震断裂的滑动速率、复发周期和构造成因[J].地球物理学报,51(4):1066-1073.
张永志.1994.地震过程中形变能的演化特征[J].地震研究,17(2):171-176.
周新,邢乐林,邹正波,等.2008.GRACE时变重力场的高斯平滑研究[J].大地测量与地球动力学,28(3):41-45.
朱广彬.2007.利用GRACE位模型研究陆地水储量的时变特征[D].北京:中国测绘科学研究院.
邹正波,邢乐林,李辉,等.2008.中国大陆及邻区GRACE卫星重力变化研究[J].大地测量与地球动力学,28(1):23-27.
Chen J L,Wilson C R,Famiglietti J S,et al.2005.Spatial sensitivity of the Gravity Recovery and Climate Experiment(GRACE)time-variable gravity observations[J].JGR.110(B9):8408–+,doi:10.1029/2004JB003536.
Han S C,Shum C K,Bevis M,et al.2006.Crustal dilation observed by GRACE after the 2004 Sumatra-Andaman earthquake[J].Sicence,313:658-662.
Reigber C,Schmidt R,Flechtner F.2005.An Earth gravity field model complete to degree and order 150 from GRACE:EIGEN-GRACE02S [J].Journal of Geodynamics,39:1-10.
Sun W,Okubo S.2004.Co-seismic deformations detectable by satellite gravity missions:A case study of Alaska(1964,2002)and Hokkaido(2003)earthquakes in the spectral domain.JGR,56:881-892.
Swenson S,Wahr J.2002.Methods for inferring regional surface mass anomalies from GRACE measurements of time-variable gravity[J].JGR 107(B9),2193,doi:10.1029/2001JB000576.
Valentin M.2004.Can tectonic processes be recovered from new gravity satellite data.Earth and Planetary Science Letters,228:281-297.

备注

引言

1 GRACE卫星监测的重力变化计算

2 汶川地震前后重力场变化

3 结语

期刊信息