珠穆朗玛峰重力值的推估──兼论推估方法的基本原理  

ESTIMATION OF THE GRAVITY IN QOMOLANGMA PEAK ──ON THE BASIC PRINCIPLE OF ESTIMATE METHOD

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,武汉430077

出　　处：《极地研究》2001年第4期273-282,共10页Chinese Journal of Polar Research

基　　金：九五攀登计划项目;国家自然科学基金项目 ( 4 9874 0 1 6 )

摘　　要：在山区 ,尤其是在有全球第三极之称的喜马拉雅山区 ,当相邻点间距不大时 ,如何利用这些点上的重力与地形 (高程 )数据推估待求点的重力值 ,这对难以攀登和不能用仪器观测的山峰很有意义。研究指出 ,在地形负荷的波长很短时 ,具有一定强度的地壳足以能够支撑这种负荷 ,因此 ,不能用Airy Heiskanen和Pratt Hayford局部补偿模型作重力推估 ;由于空间异常主要受地形起伏制约 ,因此借助于邻近重力点的地形 (高程 )作推估会得到满意的结果。基于这一思路 ,我们采用了 4种有关公式 ,有效地推估了第三极之巅珠穆朗玛峰顶上的重力值 ,该值为(976 970± 7)× 1 0 - 5m·s- 2 。这一结果为精确推求珠峰大地水准面和正高提供了必要的数据 ,若用均衡的方法来推估 ,则可能相差近 1 0 0× 1 0 - 5m·s- 2 。In this paper, we investigate the research approaches for estimating the gravity at the point, to which it is difficult for mankind to climb, and for the instrument to be carried, in the mountain area from the observed gravity and height of the nearby observation. The research results are as follows. When the wave length for the topographic load λ≤50km,The crustal strength is strong enough to keep the crust not deformed. Therefore, it is improper to use Airy Heiskanen or Pratt Hayford local compensation model to estimate the gravity. Because the free air gravity anomaly is affected by the topographic undulation, we may use the height of nearby point of known gravity to estimate the gravity. Based on this idea, utilizing four kinds of formulas, we give the gravity of Everest (976970±7)×10 -5 ms -2 , which is beneficial to the research for geoid and orthometric height, according to the view of isostasy, the deviation from result mentioned above approaches 100×10 -5 ms -2 .

关 键 词：珠穆朗玛峰 重力值 地形 地壳 大地水准面 大地测量 

分 类 号：P223.1[天文地球—大地测量学与测量工程]