チベットの地殻の薄めと流れは,地震性アニソトロピーによって制約されています
Nikolai M Shapiro1, Michael H Ritzwoller, Peter Molnar
1Center for Imaging the Earth's Interior, Department of Physics, University of Colorado at Boulder, Boulder, CO 80309, USA. nshapiro@ciei.colorado.edu
まとめ
チベット チベット チベット チベット チベット チベット
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- 地震学 地震学とは
- プレート・テクトニクス (プレート・テクトニクス)
背景:
- チベット高原の複雑な地質構造.
- 地殻の変形過程を理解する.
研究 の 目的:
- チベットの地殻アニソトロピーを調査する.
- 地殻の薄くなる程度と性質を決定する.
主な方法:
- 中間期のレイリー波とラブ波の分析.
- 地震波の伝播モデリング.
- 地震のテンソール分析. 地震のテンソール分析.
主要な成果:
- 中から下までの地殻で有意な放射性アニソトロピーが検出されました.
- 特に西チベットでは,地殻が約30%薄くなったという証拠がある.
- 地震アニソトロピーと地殻の活発な薄めとの相関.
- ミカの結晶の向きが,アニソトロピーを説明している可能性が高い.
結論:
- チベットの中から下までの地殻は,かなり薄くなっている.
- 変形は,機械的に弱い,チャネル化された流れ層を示唆しています.
- 地殻の薄めは,上層の地殻よりも中から下層の地殻でより顕著です.
関連する概念動画
Viscosity
When water is poured into a glass, it falls freely and quickly, whereas if honey or maple syrup is poured over a pancake, it flows slowly and sticks to the surface of the container. This difference in the flow of different kinds of liquids arises due to the fluid friction between the liquid layers and the liquid and the surrounding material. This property of fluids is called fluid viscosity. In this example, water has a lower viscosity than honey and maple syrup.
The SI unit of viscosity is...
The SI unit of viscosity is...
Shearing Strain
The shearing strain represents a cubic element's angular change when subjected to shearing stress. This type of stress can transform a cube into an oblique parallelepiped without influencing normal strains. The cubic element experiences a significant transformation when exposed solely to shearing stress. Its shape alters from a perfect cube into a rhomboid, clearly demonstrating the effect of shearing strain. The degree of this strain is considered positive if it reduces the angle between the...
Thin-Walled Hollow Shafts
In analyzing a thin-walled hollow shaft subjected to torsional loading, a segment with width dx is isolated for examination. Despite its equilibrium state, this segment faces torsional shearing forces at its ends. These forces are quantitatively described by the product of the longitudinal shearing stress on the segment's minor surface and the area of this surface, leading to the concept of shear flow. This shear flow is consistent throughout the structure, indicating a uniform distribution of...
Elastic Strain Energy for Normal Stresses
Strain energy quantifies the energy stored within a material due to deformation under loading conditions, a fundamental concept in materials science and engineering. The strain energy can be modeled when a material is subjected to axial loading with uniformly distributed stress. In this scenario, the stress experienced by the material is the internal force divided by the cross-sectional area, and the strain induced is directly proportional to this stress through the modulus of elasticity.
If...
If...
Elastic Strain Energy for Shearing Stresses
As discussed in previous lessons, strain energy in a material is the energy stored when it is elastically deformed, a concept crucial in materials science and mechanical engineering. This energy results from the internal work done against the cohesive forces within the material. When a material undergoes shearing stress and corresponding shearing strain, the strain energy density, which is the energy stored per unit volume, is calculated. Within the elastic limit, where the stress is...
Pressure Variation in a Fluid at Rest
In a fluid at rest, the pressure at any point beneath the fluid surface depends solely on the depth, not on the container's shape or size. This principle, known as hydrostatic pressure, arises because, in stationary fluids, there is no acceleration, meaning the forces within the fluid balance out. Only vertical forces, caused by the weight of the fluid above, contribute to pressure changes with depth.
When measuring pressure at two different levels within the fluid, the difference in pressure...
When measuring pressure at two different levels within the fluid, the difference in pressure...


