グローバル・アジムタル・シーズミック・アニソトロピーと,オーストラリアのユニークなプレート・モーション・変形
Eric Debayle1, Brian Kennett, Keith Priestley
1Institut de Physique du Globe de Strasbourg, Ecole et Observatoire des Sciences de la Terre, Centre National de la Recherche Scientifique and Université Louis Pasteur, 61084 Strasbourg, Cedex, France. Eric.Debayle@eost.u-strasbg.fr
Nature
|February 4, 2005
まとめ
大陸の根は,異なる地震性アニソトロピーを示しています. オーストラリア板は,より弱い相関関係を持つ他の大陸とは異なり,その急速な動きに関連した強いアジムタルアニソトロピーを独特に表しています.
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:
- 大陸の"根"の起源に関する議論は,高速道路の蓋の厚さの変動によるものである.
- 250~300kmの深さで観測された放射性アニソトロピーは,現在の地質プレート底辺の変形を示唆しています.
- アジムータルアニソトロピーは,変形による鉱物並びから生じ,アジムータル変動が顕著である.
研究 の 目的:
- 大陸の根形成を理解するために,地球表面波アジムタルアニソトロピーを調査する.
- アジムタルアニソトロピー,プレート運動,大陸の下の深さとの関係を決定する.
- プレート底部に重大な変形がある大陸の領域を特定する.
主な方法:
- グローバル地震トモグラフィーで地下構造をイメージする.
- 表面波アジムタルアニソトロピーの分析.
- アニソトロピーのパターンと現在のプレート運動データとの相関.
主要な成果:
- オーストラリア大陸プレートは,その急速なプレート運動 (深さ175〜300km) と強く相関する重要なアジムタルアニソトロピーを示しています.
- 他の大陸は弱いアジムータルアニソトロピーを表しており,プレート運動と相関が薄く,海洋プレートに似た深さにあります.
- 他の大陸の下のアジムタルアニソトロピーは,沈下軸のアニソトロピーにつながる単純な切断によって説明されることがあります.
結論:
- オーストラリア板は,実質的な基礎変形を持つ唯一の大陸地域であり,観測可能なアジムタルアニソトロピーを生み出しています.
- プレート運動と基礎変形は,大陸の石層におけるアジムタルアニソトロピーを生成する重要な要因である.
- アジムタルアニソトロピーの差異は,大陸の根を形作るダイナミックなプロセスについての洞察を提供します.
関連する概念動画
Variation in Acceleration due to Gravity near the Earth's Surface
An object's apparent weight is its weight measured by a spring balance at its location. It is different from its true weight, the force with which the Earth pulls it, because of the Earth's rotation. Mathematically, an object's apparent weight equals its true weight minus the centripetal force that keeps it in a circular motion along with the Earth's surface every 24 hours.
The difference between the true and apparent weights is proportional to the square of the Earth's angular speed. Since the...
The difference between the true and apparent weights is proportional to the square of the Earth's angular speed. Since the...
Resultant of a General Distributed Loading
While designing structures exposed to non-uniform loads, it is crucial to consider the resultant force and its location. This resultant force is a single vector representing the net force applied due to the distributed load.
Examples such as load distribution due to wind and load distribution on a bridge illustrate how this concept is used to analyze and design safe, reliable structures under variable loading conditions. Most structures, such as residential buildings, bridges, and towers, are...
Examples such as load distribution due to wind and load distribution on a bridge illustrate how this concept is used to analyze and design safe, reliable structures under variable loading conditions. Most structures, such as residential buildings, bridges, and towers, are...
Deformation of Member under Multiple Loadings
When a rod is made of different materials or has various cross-sections, it must be divided into parts that meet the necessary conditions for determining the deformation. These parts are each characterized by their internal force, cross-sectional area, length, and modulus of elasticity. These parameters are then used to compute the deformation of the entire rod.
In the case of a member with a variable cross-section, the strain is not constant but depends on the position. The deformation of an...
In the case of a member with a variable cross-section, the strain is not constant but depends on the position. The deformation of an...
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...
Fault Types
When analyzing a single line-to-ground fault from phase A to ground at a three-phase bus, it is important to consider the fault impedance. This impedance is zero for a bolted fault, equal to the arc impedance for an arcing fault, and represents the total fault impedance for a transmission-line insulator flashover. To derive sequence and phase currents, fault conditions are translated from the phase domain to the sequence domain.
For line-to-line faults occurring between phases B and C, the...
For line-to-line faults occurring between phases B and C, the...
Types of Building Separation Joints
Building separation joints divide large or complex building structures into smaller, discrete units that can move independently. These joints are categorized into three types: volume-change joints, settlement joints, and seismic separation joints.
Volume-change joints address the effects of expansion and contraction due to temperature and moisture variations. They are strategically placed at discontinuities in a building's mass where cracking is most likely and are spaced about 150 to 200 feet...
Volume-change joints address the effects of expansion and contraction due to temperature and moisture variations. They are strategically placed at discontinuities in a building's mass where cracking is most likely and are spaced about 150 to 200 feet...


