摘要
比较了两种不同方法,即Runcorn 方程和地幔对流模型,计算了作用于岩石层底部的切向应力场.讨论了在三种不同的边界模型下,核-幔边界对于地球大地水准面的贡献.结果表明:模型Ⅰ(自由核-幔边界;摩擦岩石层-地幔边界)和模型Ⅲ(刚性核-幔边界,摩擦岩石层-地幔边界)中,核幔边界对于地球大地水准面的贡献随球谐函数系数的增加而减少,在n≥2时可以忽略下边界的影响.而模型Ⅱ(摩擦核-幔边界,自由表面)中下边界影响不容忽视.证明使用Runcorn 方程计算岩石层底部的切向应力场是一个合理的近似.
The contributions of the core-mantle boundary and lithosphere mantle boun-
dary to the earth's geoid anomalies with different thermal convection models,
which are constrained to fit the earth's geoid anomalies are computed.The
results show that the contributions of low boundary for Model Ⅰ and Model Ⅲ
decrease with degree increasing.And the effects of low boundary to the stre-
ss field under the lithosphere can be ignored in Model Ⅰ and Model Ⅲ but not
in model Ⅱ.These results probably implicate that using Runcorn's stress eq-
uations to calculate the stress field under the lithosphere is a reesonable
approximation.
基金
国家地震基金 No.(86)008资助
