オリビンの結晶は,地球の上層マントルの拡散クリープの間に並びます
Tomonori Miyazaki1, Kenta Sueyoshi, Takehiko Hiraga
1Earthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
Nature
|October 18, 2013
まとめ
ディフュージョン・クリープだけでなく,脱位・クリープも,オリヴィン・クリスタル・アラインメントを生成します. この発見は,マントルの流れと地球の上層マントルの地震性アニソトロピーの理解に影響を与えます.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- ミネラル物理学 ミネラル物理学
- テクトニクス (地質学) とは
背景:
- オリビンの結晶学的に好ましい指向 (CPO) は,地球の上層マントルのアニソトロピーとフローを理解するために不可欠です.
- 脱位クリープは,オリヴィンCPOを生成するための伝統的に受け入れられたメカニズムです.
研究 の 目的:
- 拡散クリープがオリヴィンでCPOを生成できるかどうかを調査する.
- 拡散クリープ中のCPO発達の温度と融解の影響を決定する.
主な方法:
- 鉄のないオリビン (フォースタライト) の実験的変形は,異なる温度と融解条件下で行われました.
- 結晶学的に好ましい方向性 (CPO) のパターンの分析.
主要な成果:
- ディフュージョン・クリップはフォースタライトでCPOを生成し,そのパターンは温度と溶融の存在に依存する.
- CPOの強度は,温度と融解と相関し,粒子の境界特性と滑りに影響を与えます.
- 予測された地震アニソトロピーパターンは,観測された放射性アニソトロピーと上層マントルの地震速度の変動と一致しています.
結論:
- ディフュージョン・クリープは,オリヴィンCPOとマントルのアニソトロピーを生成するための重要なメカニズムです.
- 提案された拡散クリープモデルは,マントルの異なる温度体制における地震観測を説明する.
- これは,地震性アニソトロピーからマントルの流れを解釈する際の,脱位クリープへの唯一の依存に挑戦しています.
関連する概念動画
Imperfections in Crystal Structure: Point, Line and Plane Defects
156
A perfect crystal, in theory, has a uniform structure with the same unit cell and lattice points throughout. However, any deviation from this periodic arrangement is known as an imperfection or defect. These defects can be categorized into three types: point, line, and plane defects.Point defects occur when there is a deviation from the ideal due to missing atoms, displaced atoms, or additional atoms. These imperfections might occur due to imperfect packing during crystallization or because of...
156
Lattice Energies of Ionic Crystals
20
Lattice energy represents the energy released when gaseous cations and anions combine to form an ionic solid, reflecting the strength of electrostatic interactions within the crystal. This process is fundamentally governed by Coulombic attraction between oppositely charged ions, where the potential energy varies inversely with the interionic distance and directly with the product of ionic charges. As ions approach one another, the electrostatic energy becomes increasingly negative, indicating a...
20
Symmetry Elements in a Crystal
32
Crystal symmetry operations are isometric transformations that map objects onto indistinguishable copies while preserving distances, angles, and volumes. The simplest symmetry operation is translation, which shifts the entire infinite crystal lattice parallelly by a translation vector.Crystallographic rotations involve rotations by an angle of 2π/n around an axis without changing the positions of points on the axis. It is called the rotational axis of the symmetry, denoted by n. The...
32
Crystal Growth: Principles of Crystallization
5.7K
Crystallization is a phase transformation process in which crystals are precipitated from a supersaturated solution or formed from other sources. During crystallization, atoms or molecules arrange themselves into a well-defined, rigid crystal lattice to minimize energy.
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
5.7K
Imperfections in Crystal Structure: Non-Stoichiometric Defects
117
Non-stoichiometric defects refer to a type of defect in the crystal structure of a compound where the ratio of its constituent elements deviates from the ideal stoichiometric ratio. There are two main types of non-stoichiometric defects: metal excess defects and metal deficiency defects.Metal excess defects occur when there is a slight surplus of metal ions than what is required by the stoichiometric ratio of the compound. For example, heating a sodium chloride crystal in sodium vapor results...
117
Imperfections in Crystal Structure: Stoichiometric Point Defects
147
Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...
147


