当今地球地幔结构是由基底岩海洋的地污染造成的
Maxim D Ballmer1, Rob J Spaargaren2,3, Ananya Mallik4
1Dept. Earth Sciences, University College London, London WC1E 6BT, UK.
Science advances
|July 18, 2025
概括
地球的深层地幔结构,大低速省 (LLVPs),可能是由污染的基底岩海洋 (BMO) 形成的,而不是简单的分数结晶. 这种反应性结晶模型更好地解释了LLVP的特性,并预测了地球深层的组成.
科学领域:
- 行星科学 行星科学
- 地质物理学 地质物理学
- 地质化学 地质化学
背景情况:
- 早期地球上的岩海洋结晶,在核心上形成了基底岩海洋 (BMO).
- 地震数据表明火星和月球上的BMO,但地球的基本上是固化的.
- 地球下层地幔中的大型低速度省 (LLVPs) 与BMO分量结晶有关.
研究的目的:
- 研究LLVPs的形成机制,并将其属性与BMO结晶模型相协调.
- 为了测试反应性结晶,而不仅仅是分量结晶,塑造了深层地幔的假设.
- 为了预测地球深层地震异常和潜在的BMO残留物的组成.
主要方法:
- 基本岩海洋结晶的热力学建模.
- 对LLVP体积,密度和组成的分析.
- 模型预测与地震观测的比较.
主要成果:
- 一个BMO的分量结晶产生较低的地幔密度与观察到的LLVPs不一致.
- 反应性结晶,包括添加回收的玄武岩地,成功地调和了LLVP的特性.
- 该模型预测了超低速度区域和潜在的BMO残留物的组成.
结论:
- 地污染和反应性结晶对于解释LLVP的形成和特征至关重要.
- 这个模型阐明了BMO在火星上的持久性.
- 相似的过程意味着与地球相比,金星的BMO的命运不同.
相关概念视频
The Soil Ecosystem
21.8K
Plants obtain inorganic minerals and water from the soil, which acts as a natural medium for land plants. The composition and quality of soil depend not only on the chemical constituents but also on the presence of living organisms. In general, soils contain three major components:
21.8K
Magnetostatic Boundary Conditions
1.1K
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
1.1K
Diversity of Protists III
135
Rhizaria are a diverse group of unicellular protists characterized by their threadlike cytoplasmic extensions known as pseudopodia. These structures aid in both locomotion and feeding, giving Rhizaria an amoeboid appearance. Their amoeboid morphology once led to taxonomic confusion, but molecular phylogenetics has clarified their evolutionary placement and emphasized their shared use of pseudopodia despite divergent lineages.This clade comprises diverse lineages such as Chlorarachniophyta,...
135
The Sulfur Cycle
46.3K
Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the atmosphere as sulfur dioxide (SO2), sulfur is released by decaying organisms, weathered rocks, geothermal vents, volcanos, and burning fossil fuels. It is deposited into the ecosystem, cycled through the biotic community, and either released back into the atmosphere as gas or deposited in marine sediment for long-term storage and eventual...
46.3K
Influence of Earth's Curvature and Atmospheric Refraction on Leveling
280
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance.
280
Global Climate Change
24.8K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
24.8K


