地壳对不同波长地形在重力场中的响应  

The gravity responce in crust on different wavelength topography

作　　者：张赤军[1] 

机构地区：[1]中国科学院测量与地球物理研究所,湖北430077

出　　处：《地球物理学进展》2003年第2期342-347,共6页Progress in Geophysics

基　　金：中国科学院创新项目 (KZCX2-10 6)资助 .

摘　　要：为有效发挥重力均衡在地质、地球物理和大地测量中的作用 ,本文进一步阐明重力位球函数的阶数与波长的关系 ,以及地形及其补偿与波长的关系 .指出在研究短波长地形的重力效应时无需考虑补偿的影响 ,否则将会引起场效应的失真 .模型的研究表明 ,在局部地区或测点上 ,利用高程资料作重力异常推估可以达到理想的结果 .为检验均衡理论的适用性与局限性 ,文中列出高喜马拉雅一带的 5 4块样品的岩石密度和岩性 ;为验证地形的重力效应 ,还计算出锥形山体对外部点的引力 .In order to fruitfully and exactly exert gravity isostasy on geology, geophysics and geodesy, the relation between order(n) of spherical harmonics and Wavelength is explained, the relation between topography with its compensation and wavelength is also described, Investigating the influences of short wave topography on gravity field, the effect of compensation is not necessary regarded, otherwise it will be distorted the field effect. Model result researched shows that using topographic height to estimate gravity anomalies can obtain idea result of gravity field. For checking the exactitude of Pratt model, the density and property of a number of rocks in high Himalaya has been listed. The gravitation of a point located respectively outside circular cylinder and conic body have been calculated. It should be added that the crust is possessed of strength, and there are a numbers of topography mass located on it, if it's dimension is replaced by wave length λ, then some conclusions can be got, when the λ is larger than 1000km, the topographic mass can get regional compensation when the λ is less than 75kms, the topographic mass can's get compensation i.e., the compensation effect is almost equal to zero.

关 键 词：波长 地形 重力均衡 

分 类 号：P312[天文地球—固体地球物理学]