Effects of water load on geophysical signals due to glacial rebound and implications for mantle viscosity
Effects of water load on geophysical signals due to glacial rebound and implications for mantle viscosity
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冰川回弹引起的水负荷对地球物理信号的影响及其对地幔粘度的影响
DOI：
10.1186/bf03352408
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
M. Nakada
中科院分区：
文献类型：
--
作者：
J. Okuno;M. Nakada
我们调查的影响，海洋功能的海平面变化和其他地球物理信号的预测，由于冰川反弹。为了准确地预测这些信号，一个现实的海洋功能，包括古地形的影响，冰盖和融水流入的分布是必需的。在哈德逊湾观测资料的模拟中，采用一个精确的海洋函数对于下地幔粘度为1021 Pa·s的地球模式是非常重要的。在这种情况下，水荷载的贡献可以与冰荷载的贡献相媲美。然而，在芬诺斯堪的纳维亚地区，预测对海洋功能的细节不太敏感，因为波的尼亚湾的宽度与哈德逊湾相比非常小。在假设冰模型为ARC 3 + ANT 4 b的情况下，利用北美和北方欧洲的相对海平面、重力异常和固体表面重力变化，研究了粘性结构。研究表明，下地幔粘度大于1022 Pa·s，上地幔粘度为（4 × 10）× 1020 Pa·s。
We investigate the effects of the ocean function on predictions of the sea-level changes and other geophysical signals due to glacial rebound. To precisely predict these signals, a realistic ocean function including the effects of the palaeotopography, the distribution of ice sheet and meltwater influx is required. The adoption of a precise ocean function is very important in simulating the observables in Hudson Bay for an earth model with a low lower mantle viscosity of ∼1021 Pa s. In this case, the contribution from water loads can be comparable to that from ice loads. In the Fennoscandian region, however, the predictions are less sensitive to the details of the ocean function, because the width of the Gulf of Bothnia is very small compared with that of Hudson Bay. With an assumption that the ice model is represented by ARC3+ANT4b, we have examined the viscosity structure using relative sea-levels, gravity anomaly and solid surface gravity changes in North America and northern Europe. This study suggests a lower mantle viscosity of greater than 1022 Pa s and a upper mantle viscosity of (4 ∼ 10) × 1020 Pa s.