まとめ
地震データによると,ヨーロッパの下には,マントルの上部に独特な構造があります. 鋭い境界線が冷たい,高速なプレキャンブリアクレートンと,より暑い,低速度なファネロゾイク領域を分離しており,アステノスフィアの物質輸送が限られていることを示しています.
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
- 地球科学 地球科学 地球科学
背景:
- ヨーロッパの下の上層マントルの構造は,大きな変化を示しています.
- これらの変異を理解することは,構造の歴史とプロセスを解読する鍵です.
研究 の 目的:
- ヨーロッパの下の上層マントルの地震特性を調査する.
- プレキャンブリアクレートンと,より若いヨーロッパ地域との境界線を描画する.
主な方法:
- 地震学データの分析.
- シェア波速度の解釈により,温度と組成を推測する.
主要な成果:
- プレカンブリアとファネロゾイク時代のヨーロッパには,地震特性の明らかな相違がある.
- プレキャンブリアクレートンは,低温を暗示する,高いシェア波速度を示している.
- 低地震速度はファネロゾーイクヨーロッパの下部で観測され,少なくとも140kmの深さまで広がっています.
結論:
- 複雑な地質学の歴史にもかかわらず,地震の移行地帯は著しく鋭い.
- この鋭さは,アステノスフィアの物質がクラトン境界を横切って横向きに運ばれることが最小限であることを示唆しています.
関連する概念動画
Formation of the Platelet Plug
The platelet phase, the second stage of hemostasis, commences around 15-20 seconds after an injury. It follows and overlaps with the vascular phase, during which blood vessels constrict to minimize blood loss.
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
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...
Fluid Pressure over Flat Plate of Variable Width
When a flat plate is submerged in a fluid, the fluid exerts pressure on the plate. This pressure can lead to many different phenomena, including drag and buoyancy. To understand the behavior of the fluid over a flat plate of variable width, it is essential to analyze the distribution of the pressure exerted.
The pressure distribution on the plate can be calculated by determining the force that acts on a differential area strip of the plate. Thus, the magnitude of the force is equal to the...
The pressure distribution on the plate can be calculated by determining the force that acts on a differential area strip of the plate. Thus, the magnitude of the force is equal to the...
Deep Sea Microbial Ecology
The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...
Fluid Pressure over Flat Plate of Constant Width
When a body is submerged in water, it experiences fluid pressure acting normal on its surface and distributed over its area. For better design structures, it is crucial to determine the magnitude and location of the resultant force acting on the surface. In the case of a rectangular plate of constant width submerged in water, the pressure increases with depth, resulting in a linearly varying trapezoidal pressure distribution from the upper to the lower edge of the plate.
The resultant force...
The resultant force...
Fluid Pressure over Curved Plate of Constant Width
When a curved plate of constant width is submerged in a liquid, the pressure acting normal to the plate varies continuously both in magnitude and direction. Calculating the magnitude and location of the resultant force at a point is often challenging for such cases. One of the methods to determine the resultant force and its location involves separately calculating the horizontal and vertical components of the resultant force. This complex calculation can be simplified by representing the...


