摘要
讨论了重力场的大地奇异性条件及其在地固直角坐标系中的表达式。利用简化的球对称地球模型研究了大地奇异性结构与场源物理结构的关系，结果表明：只有在扰动区域密度低于周围环境密度，且扰动场源密度与地球平均密度之比不小于扰动体埋深与半经之比的３次幂时，地球外部才存在奇异点；所有奇异点构成两个倒扣在地球上的旋转抛物面状曲面；对ＰＲＥＭ地球模型而言，内部密度扰动将不会产生外部奇异性。
Geodetic singularity condition is discussed in this paper,and the formulation about it in Cartesian coordinates is presented.And then,the relationship between geodetic singularities and physical structure of the source concerning a simpeified model is discussed in detail.The results show that singularity points exist outside the model only upon condition that the density of the disturbing aera is not larger than that of the surrounding area andδρρm<-(hr) 3. As to PREM,density disturbing inside the model can′t produce singularity outside the model.
出处
《地壳形变与地震》
CSCD
1998年第1期1-7,共7页
Crustal Deformation and Earthquake
基金
国家自然科学基金
现代地球动力学实验室资助
关键词
大地奇异性结构
场源物理结构
重力场
geodetic singularity ,physical structure of the source,Gauss curvature,inhomogeneous spherical model
