GRACE卫星时变重力场的小波多尺度分解——以2008年汶川Ms8.0大地震为例
|
摘要
根据UTCSR发布的GRACE卫星资料,计算了汶川及其周边地区的卫星时变重力场,并利用小波多尺度分析方法对卫星重力场进行分解,得到了反映不同深度的重力场细节和逼近。通过研究各个细节和逼近成分的重力场变化,结合区域构造运动的特点,对GRACE观测的时变重力场及汶川地震的动力机制进行了初步解释和讨论。结果表明,4阶细节和4阶逼近较好地揭示了汶川地区构造形变和深部物质流动引起的重力变化,而且这种震前重力变化特征满足地震孕育发生的条件。
The time variable gravity in Wenchuan and its surrounding areas was calculated by using the GRACE data published by UTCSR.Then the multi-scale wavelet analysis was used to decompose the satellite gravity field,therefore,details and approximations reflecting different depth of geological bodies were obtained.By studying changes in the gravity field of every detail and approximation component,combining with the features of regional tectonic movement,a preliminary explanation and discussion on the features of time variable gravity as well as the dynamic mechanism of Wenchuan earthquake was presented.The results show that the change in gravity which caused by the tectonic deformation and deep mass transfer in Wenchuan area is revealed effectively by the fourth-order detail and approximation.Moreover,the features of changes in gravity before earthquake meet the conditions of earthquake preparation and occurrence.
The time variable gravity in Wenchuan and its surrounding areas was calculated by using the GRACE data published by UTCSR.Then the multi-scale wavelet analysis was used to decompose the satellite gravity field,therefore,details and approximations reflecting different depth of geological bodies were obtained.By studying changes in the gravity field of every detail and approximation component,combining with the features of regional tectonic movement,a preliminary explanation and discussion on the features of time variable gravity as well as the dynamic mechanism of Wenchuan earthquake was presented.The results show that the change in gravity which caused by the tectonic deformation and deep mass transfer in Wenchuan area is revealed effectively by the fourth-order detail and approximation.Moreover,the features of changes in gravity before earthquake meet the conditions of earthquake preparation and occurrence.
引文
[1]Sun W,Okubo S.Co-seismic Deformations Detecta-ble by Satellitegravity Missions:a Case Study ofAlaska(1964,2002)and Hokkaido(2003)Earth-quakes in the Spectral domain[J].Geophys Res,2004,56:881-892
[2]段虎荣,张永志,刘锋,等.利用GRACE卫星数据研究汶川地震前后重力场的变化[J].地震研究,2009,32(3):295-298
[3]王武星,石耀霖,顾国华,等.GRACE卫星观测到的与汶川Ms8.0地震有关的重力变化[J].地球物理学报,2010,53(8):1697-1777
[4]周旭华,吴斌,彭碧波,等.全球储水量变化的GRACE卫星检测[J].地球物理学报,2006,49(6):1 644-1 650
[5]宁津生,罗佳,汪海洪.GRACE模式确定重力场的关键技术探讨[J].武汉大学学报.信息科学版,2003,28(S1):13-17
[6]高德章,侯遵泽,唐建.东海及邻区重力异常小波多尺度分解[J].地球物理学报,2000,40(6):842-849
[7]杨文采,施志群,侯遵泽.离散小波变化与重力异常多重分解[J].地球物理学报,2001,44(4):534-541
[8]秦前清,杨宗凯.实用小波分析[M].西安:西安电子科技大学出版社,1994
[9]Bhattacharyya B K.Spectral Analysis of Gravityand Magnetic Anomalies Due to Two DimensionalStructures[J].Geophysics,1975,40(6):993-1 013
[10]邢乐林,李建成,李辉,等.Sumatra-Adaman大地震同震和震后形变的GRACE卫星检测[J].武汉大学学报.信息科学版,2009,34(9):1080-1084
[11]李延兴,张静华,周伟,等.汶川Ms8.0地震孕育发生的机制与动力学问题[J].地球物理学报,2009,52(2):519-530
[12]申重阳,李辉,孙少安,等.重力场动态变化与汶川Ms8.0地震孕育过程[J].地球物理学报,2009,52(10):2 547-2 557
[2]段虎荣,张永志,刘锋,等.利用GRACE卫星数据研究汶川地震前后重力场的变化[J].地震研究,2009,32(3):295-298
[3]王武星,石耀霖,顾国华,等.GRACE卫星观测到的与汶川Ms8.0地震有关的重力变化[J].地球物理学报,2010,53(8):1697-1777
[4]周旭华,吴斌,彭碧波,等.全球储水量变化的GRACE卫星检测[J].地球物理学报,2006,49(6):1 644-1 650
[5]宁津生,罗佳,汪海洪.GRACE模式确定重力场的关键技术探讨[J].武汉大学学报.信息科学版,2003,28(S1):13-17
[6]高德章,侯遵泽,唐建.东海及邻区重力异常小波多尺度分解[J].地球物理学报,2000,40(6):842-849
[7]杨文采,施志群,侯遵泽.离散小波变化与重力异常多重分解[J].地球物理学报,2001,44(4):534-541
[8]秦前清,杨宗凯.实用小波分析[M].西安:西安电子科技大学出版社,1994
[9]Bhattacharyya B K.Spectral Analysis of Gravityand Magnetic Anomalies Due to Two DimensionalStructures[J].Geophysics,1975,40(6):993-1 013
[10]邢乐林,李建成,李辉,等.Sumatra-Adaman大地震同震和震后形变的GRACE卫星检测[J].武汉大学学报.信息科学版,2009,34(9):1080-1084
[11]李延兴,张静华,周伟,等.汶川Ms8.0地震孕育发生的机制与动力学问题[J].地球物理学报,2009,52(2):519-530
[12]申重阳,李辉,孙少安,等.重力场动态变化与汶川Ms8.0地震孕育过程[J].地球物理学报,2009,52(10):2 547-2 557
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