海洋底の地震データから推定されたマリアナ海域への水流入量
Chen Cai1, Douglas A Wiens2, Weisen Shen2,3
1Department of Earth and Planetary Sciences, Washington University in St Louis, St Louis, MO, USA. cai.chen@wustl.edu.
Nature
|November 16, 2018
まとめ
サブドクションゾーンは地球に深く水を運ぶが,この水の流れに関する以前の推定は不確実だった. 新しい地震データは,以前考えられていたよりも,かなり多くの水路を明らかにし,世界的な見積もりを見直しています.
科学分野:
- 地理学
- 地球科学
- 地震学
背景:
- 地球の深層の水循環は十分に理解されていないが,沈殿地における水流の推定には大きな不確実性がある.
- 以前の地震研究は,沈殿板の水分化を示唆したが,特に古い板には深さの制約がなかった.
研究 の 目的:
- 地震データを用いて マリアナ海溝の下のマントルの水分化の範囲を調査する.
- 地球のマントルへの水の浸透の見積もりを精査する.
主な方法:
- 海底の地震データからのレイリー波分散の分析.
- マリアナ海溝周辺の地殻と最上層のマントルの地震画像の生成
主要な成果:
- 地震画像は,マントルの水分がモホの不連続性の下まで約24kmまで広がっていることを示しています.
- 計算された水浸層は,この地域の以前の推定値の少なくとも4.3倍です.
- マントル (深さ100km) への全体的な水流の推定値は3倍にする必要があるかもしれません.
結論:
- 古い冷たい沈殿板は,以前に推定されたよりはるかに多くの水を運ぶ可能性があります.
- 地球の深層の水循環の理解に 影響を及ぼしています
- 火山の弧とバックアークの盆地での水排出の向上修正は,おそらく必要である.
関連する概念動画
Hybrid Zones
21.9K
Hybrid zones are narrow regions where two closely related species interact, mate, and produce hybrids. Relative to either parent species, hybrids may possess distinct phenotypic or genetic differences that impact their survival and reproductive success. The genetic variances introduced by hybridization influence species diversity and speciation processes within the hybrid zone.
21.9K
The Water Cycle
28.5K
The Earth’s hydrosphere includes all of the areas where the storage and movement of water occurs. Since water is the basis of all living processes, the cycling of water is extremely important to ecosystem dynamics.
28.5K
Zones of Protection
798
In power systems, the entire setup is divided into protective zones to isolate faults and protect the rest of the network. These zones include generators, transformers, buses, transmission lines, distribution lines, and motors. Each zone can be visualized as a separate room in a house, with each room protected by its own circuit breaker.
Protective zones are defined by closed dashed lines, containing one or more components. A key characteristic of these zones is the strategic placement of...
Protective zones are defined by closed dashed lines, containing one or more components. A key characteristic of these zones is the strategic placement of...
798
Transition Zone
387
The transition zone in concrete is a critical area where aggregate meets cement paste, marked by a distinct porosity and weakness compared to the surrounding material. The adhesion around the aggregates is primarily due to Van Der Waals forces. The voids within this zone influence its robustness; initially, it is less durable than the surrounding bulk mortar due to larger voids. Initially, when concrete is compacted, a higher water-cement ratio near the aggregates leads to the formation of...
387
What are Estimates?
8.8K
It isn't easy to measure a parameter such as the mean height or the mean weight of a population. So, we draw samples from the population and calculate the mean height or mean weight of the individuals in the sample. This sample data acts as a representative measure of the population parameter. These sample statistics are known as estimates.
The estimate for the mean of a sample is denoted by ͞x, whereas the mean of the population is designated as μ. Further, parameters such...
The estimate for the mean of a sample is denoted by ͞x, whereas the mean of the population is designated as μ. Further, parameters such...
8.8K
States of Water
56.9K
Water exists in any one of the three classical states: solid (ice), liquid (water), and gas (steam or water vapor). The state of water depends on i) the intermolecular forces that draw molecules together and ii) the kinetic energy that leads to movements that pull them apart.
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
56.9K


