An Analysis of Gravitational Gradients in Rotated Frames and Their Relation to Oriented Mass Sources
An Analysis of Gravitational Gradients in Rotated Frames and Their Relation to Oriented Mass Sources
复制标题
旋转框架中的引力梯度分析及其与定向质量源的关系
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
I. Panet
中科院分区：
文献类型：
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作者：
I. Panet
地球及其流体包层内的许多质量源显示出细长的几何形状，例如与板块边界和板块运动、海岸线、河流和流域盆地的方向一致。为了加强全球或区域重力观测和模型中它们的识别和分离，本文提出了一种基于重力梯度分析的专用方法。这种方法提供了重力变化地理模式的详细描述，由于高精度卫星数据的规则空间覆盖，重力变化的地理模式被准确地绘制出来，并且是由地球内的横向密度变化引起的。首先，重力梯度在球形框架中的不同空间尺度上定义，球形框架根据源的方向沿径向轴旋转。描述了这些梯度对球形地球内部质量分布的敏感性，并介绍了将源与可观测值相关的解析表达式。然后，研究了不同空间尺度上的重力梯度对位于表面和不断增加的深度的平坦基本质量源的响应。具体来说，本文研究了如何确定具有不同宽度与长度纵横比的局部和振荡质量异常的源宽度和方向。本理论案例研究旨在将所提出的方法应用于静态或时变卫星重力场模型时，为分析更复杂的质量结构提供基础。通过检测重力场中有意义的几何形状和方向，可能有助于破译重力源的性质。
Many mass sources within the Earth and its fluid envelopes show elongated geometries, aligning with the orientations of plate boundaries and plate motions, coastlines, rivers, and drainage basins for instance. To enhance their identification and separation in global or regional gravity observations and models, a dedicated method based on gravitational gradients analysis is presented here. This approach provides a detailed description of the geographic pattern of the gravity variations, which are accurately mapped thanks to the regular spatial coverage of high‐accuracy satellite data and arise from lateral density changes within the planet. First, gravity gradients are defined at different spatial scales in spherical frames, which are rotated along the radial axis according to the orientation of the source. The sensitivity of these gradients to the mass distribution inside a spherical Earth is described and analytical expressions relating the source to the observable are introduced. Then, the gravity gradients responses at different spatial scales to flat, elementary mass sources located at the surface and at increasing depth are studied. Specifically, the paper investigates how a source width and orientation can be determined, for localized and oscillatory mass anomalies with different width‐to‐length aspect ratios. This theoretical case study aims at providing a basis for the analysis of more complex mass structures, when applying the presented method to static or time‐varying satellite gravity field models. It may help deciphering the nature of the gravity sources by the detection of meaningful geometries and orientations in the gravity field.
影响因子：
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作者：
I. Panet;A. Chambodut;M. Diament;M. Holschneider;O. Jamet
通讯作者：
I. Panet;A. Chambodut;M. Diament;M. Holschneider;O. Jamet