来自全球动态模型的板块运动和应力
Attreyee Ghosh1, William E Holt
1Geosciences Department, Stony Brook University, Stony Brook, NY 11794, USA. atreig@gmail.com
概括
这项研究提出了一个全球动态模型,通过结合地球的浅层结构和地幔流动,准确预测板块运动和应力. 这些发现揭示了这些因素是如何推动或抵制全球构造板块运动的.
科学领域:
- 地质物理学 地质物理学
- 构造学 构造学 构造学 构造学
- 计算建模 计算建模
背景情况:
- 了解构造板块运动驱动因素对于地球科学至关重要.
- 预测板块运动,变形和应力是数值建模中的一个挑战.
研究的目的:
- 开发一个全球动态模型来预测板块运动和相关参数.
- 为了研究浅层地球结构和地幔流动对板块构造学的影响.
主要方法:
- 开发了一个包含横向粘度变化 (顶部200公里) 的全球动态模型.
- 包括地形,石质层结构和地幔流量合的力量.
- 根据全球观测板块运动和应力进行验证的模型.
主要成果:
- 该模型准确地适应了板块运动,边界变形,刚性和应力等参数.
- 证明浅层结构与地幔流的相对重要性在地理上有所不同.
- 确定了地幔流驱动或抵制板块运动的区域.
- 显示的沉积板不需要强大的应力导向来匹配观测.
结论:
- 侧面粘度变化和地幔流量合是准确建模板块构造学的关键.
- 浅层地球结构和深层地幔动态之间的相互作用决定了板块的行为.
- 全球板块运动和应力可以解释,而不需要依赖于浮板块强烈的应力导向效应.
相关概念视频
Stress: General Loading Conditions
To grasp the intricacy of real-world conditions where multiple loads are applied simultaneously to a structure, one might visualize a section passing through a specific point within a body, aligned parallel to the xy plane. This section is subjected to various forces, including original loads, normal forces, and shearing forces.
The shearing force, possessing potential directionality within the plane of the section, is simplified into two component forces running parallel to the x and y axes.
The shearing force, possessing potential directionality within the plane of the section, is simplified into two component forces running parallel to the x and y axes.
Principal Stresses
The graphical depiction of normal and shearing stress equations is represented by a circle, demonstrating the interplay between these stresses under different angular conditions. The center of this circle C, located on the vertical axis, represents the average normal stress, while its radius shows the range of stress variations. At points A and B, where the circle intersects the horizontal axis, the maximum and minimum normal stresses are observed, occurring without shearing stress. These...
Transformation of Plane Stress
Studying stress transformation is essential in understanding how stress components within a material, like a cube under plane stress, change with rotation. This change is analyzed by considering a prismatic element within the cube. As the element rotates, the stress components acting on it—both normal and shearing stresses—change in magnitude and orientation. This change is quantified using trigonometric functions of the rotation angle, relating the forces acting on the rotated element's faces...
General State of Stress
The general state of stress within a material can be accurately depicted using a stress tensor. This tensor encapsulates the internal forces distributed within a material subjected to external forces or deformations.
Specifically, consider a tetrahedral element where one face, labeled XYZ, is perpendicular to the line OA, and the remaining faces align with the coordinate axes with point O as the origin. At any point, such as point O, the stress tensor can be used to determine the stress...
Specifically, consider a tetrahedral element where one face, labeled XYZ, is perpendicular to the line OA, and the remaining faces align with the coordinate axes with point O as the origin. At any point, such as point O, the stress tensor can be used to determine the stress...
Stresses under Combined Loadings
When analyzing a bent tube with a circular cross-section subjected to multiple forces, it is crucial to determine the stress distribution in order to maintain structural integrity under varied load conditions.
The process begins by slicing the tube at critical points and analyzing the internal forces and stress components at these sections, focusing on the centroid. Normal stresses, generated by axial forces and bending moments, are either compressive or tensile and vary across the section from...
The process begins by slicing the tube at critical points and analyzing the internal forces and stress components at these sections, focusing on the centroid. Normal stresses, generated by axial forces and bending moments, are either compressive or tensile and vary across the section from...
Principal Stresses: Problem Solving
When analyzing two planes intersecting at right angles under the influence of shearing, tensile, and compressive stresses, it is essential to identify principal planes, maximum shearing stress, and principal stresses. To find the principal planes, apply a formula that equates them to twice the shearing stress divided by the difference between tensile and compressive stresses.

