摘要
由于卫星观测技术的发展 ,现在已能利用测高大地水准面简捷可靠地研究海底构造与动力问题 .根据GeosatT2 ERM、Topex Poseidon和ERS 1 2测高数据给定的 0°N～ 4 5°N、10 0°E～ 15 0°E范围内 4′× 4′大地水准面 ,采用全球地形 均衡的重力位效应改正 ,计算布格、格莱尼和均衡大地水准面 .由格莱尼大地水准面反演Moho面埋深 ,再从均衡大地水准面起伏推算小尺度地幔流应力场 .结果表明 ,菲律宾海和南海显示了与磁条带、扩张脊对应或斜交的高频成分大地水准面起伏条带 .各边缘海盆的Moho面埋深有往南变浅的趋势 ,与菲律宾海各海盆的Moho面埋深大致相当 ,说明琉球—台湾—菲律宾岛弧两侧的构造动力强度基本相近 .从各种构造特征和大、中、小尺度的地幔流应力场的驱动机制 ,可以证明岛弧内侧的边缘海具有不同于大洋、大陆的独特构造动力格局和特征 .
With the rapid development of satellite observations, we can use the altimetry geoid to study submarine tectonics and geodynamics. On the basis of the 4′×4′ geoid undulation calculated from altimeter data of Geosat, ERS-1/2 and Topex/Poseidon on the West Pacific, located between 0°N～45°N, 100°E～150°E, Bouguer, Glenni and isostatic geoid undulation are obtained from correction of gravitational potential of the global topography and isostacy. Moho discontinuity depth is inversed by the Glenni geoid undulation, and the stress field from small-scale mantle convection is reasonably calculated from the isostatic geoid undulation. The results show that within the Philippine Sea and the South China Sea, short- wavelength lineations of the geoid undulation are parallel or cross to magnetic lineations and rifting ridges. The Moho depth of marginal sea basins becomes shallow southward, and its values are similar to that of the Philippine Sea. These facts show that strength of tectonic activities are almost the same on the both sides of the Ryukyu—Taiwan—Philippine arc. Various kinds of tectonic features with different driving mechanisms of small-middle and large-scale of mantle convection, however, display a special pattern of tectonics and geodynamics of the continental marginal seas distinguished from oceans and continents.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第5期600-608,共9页
Chinese Journal of Geophysics
基金
国家重点基础研究发展规划项目 (G2 0 0 0 0 4670 3 )
关键词
测高大地水准面
构造动力格局
边缘海
西太平洋
Altimetric geoid, Tectonic/Geodynamic pattern, Marginal sea, West Pacific.
