2018年のキラウエアの噴火時のマグマ粘度を示す地震
D C Roman1, A Soldati2, D B Dingwell2
1Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, USA. droman@carnegiescience.edu.
Nature
|April 8, 2021
まとめ
地震の断層平面の解はマグマの粘度を示し,火山噴火のスタイルを予測するのに役立ちます. キラウエアの回転した断層平面の溶液は,マグマの高粘度を示唆し,新しい噴火の前駆体を提供します.
科学分野:
- 地理学
- 火山学
- レオロギー
背景:
- マグマの粘度が火山噴火のスタイルと危険性を決定しますが,通常は噴火後に測定されます.
- 噴火スタイルを予測するには,マグマの粘度を示す前駆者を特定する必要があります.
- 2018年のキラウエア噴火は異常な溶岩の変動を示し,予測不能な噴火動力をもたらした.
研究 の 目的:
- 地震の断層平面の溶液とマグマの粘度との関係を調査する.
- 火山の噴火様式を予測するための先駆者を特定する.
- 噴火中の地震活動におけるマグマのレオロギーの役割を理解する.
主な方法:
- 地震性とマグマの整合分析
- 2018年のキラウエア噴火の前の地震からの断層平面解の検討.
- 2018年のキラウエア噴火の産物と以前の溶岩の粘度測定.
主要な成果:
- 2018年のキラウエア噴火中の地震断層平面の解き方は,90度のストレスフィールドの回転を示した.
- このストレスフィールドの回転は,以前は高粘度噴火のみに関連付けられた現象です.
- 局所的なストレスフィールドの方向転換を誘導するための特定の粘度値が特定されました.
結論:
- 地震群の回転した断層平面溶液は,マグマの粘度が上昇した早期警告として機能します.
- 断層平面の解決方向をリアルタイムで監視することで,噴火のあり方についての重要な洞察が得られます.
- 多段階の火山のシステムにおける 断裂と流れの組み合わせについて 根本的な洞察を提供している.
関連する概念動画
01:20Elasticity in Concrete
202
Upon subjecting concrete to moderate or high uniaxial compressive or tensile stresses, the strain response is non-linear relative to the stress applied. As the stress is removed, the resulting stress-strain curve deviates from the original path traced during loading, creating a hysteresis loop, indicative of the concrete's non-linear and non-elastic properties. Typically, a material's modulus of elasticity, which is a measure of the material's stiffness, is inferred from the linear...
202
01:17Soundness of Cement
319
The soundness of cement refers to the ability of cement paste to retain its volume after setting. Unsound cement can lead to expansion and structural damage due to the presence of free lime, magnesia, and calcium sulfate. Free lime hydrates very slowly, expanding and causing unsoundness, which is difficult to detect because it intercrystallizes with other compounds. Magnesia also reacts with water, forming crystals that can disrupt the cement's structure. Calcium sulfate can create...
319
01:16Dynamic Modulus of Elasticity of Concrete
675
The dynamic modulus of elasticity assesses how a concrete structure deforms under impact or dynamic loads. It is typically higher than the static modulus of elasticity, measured under slow, steady loading conditions.
The sonic test is a common method to determine the dynamic modulus. In this test, a concrete beam, sized either 6 x 6 x 30 inches or 4 x 4 x 20 inches, is clamped at its center. Vibrations are initiated at one end of the beam by an electromagnetic exciter unit powered by a...
The sonic test is a common method to determine the dynamic modulus. In this test, a concrete beam, sized either 6 x 6 x 30 inches or 4 x 4 x 20 inches, is clamped at its center. Vibrations are initiated at one end of the beam by an electromagnetic exciter unit powered by a...
675
01:15Strain and Elastic Modulus
6.0K
The quantity that describes the deformation of a body under stress is known as strain. Strain is given as a fractional change in either length, volume, or geometry under tensile, volume (also known as bulk), or shear stress, respectively, and is a dimensionless quantity. The strain experienced by a body under tensile or compressive stress is called tensile or compressive strain, respectively. In contrast, the strain experienced under bulk stress and shear stress is known as volume and shear...
6.0K
01:15Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
392
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
392
01:31Magnetic Susceptibility and Permeability
1.8K
In linear magnetic materials, like paramagnets and diamagnets, magnetization is proportional to the magnetic field intensity. The constant of proportionality, a dimensionless number, is called magnetic susceptibility. The value of the susceptibility depends on the type of material.
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
1.8K