地质物理和地化学证据表明,在中海山脊下面的深度温度变化
Colleen A Dalton1, Charles H Langmuir, Allison Gale
1Department of Earth and Environment, Boston University, 685 Commonwealth Avenue, Boston, MA 02215, USA.
概括
地球地幔温度变化超过250°C,深度超过400公里,影响地幔对流和海洋盆地深度. 这项研究整合了地震数据,山脊深度和玄武岩组成,以揭示全球热模式.
科学领域:
- 地质物理学 地质物理学
- 地球科学 地球科学 地球科学
- 行星科学 行星科学
背景情况:
- 地幔的温度和组成从根本上控制着地球的特性,比如对流力和海洋盆地的深度.
- 地震波速,海洋脊的深度和中洋脊的玄武岩组成是地幔变化的关键指标.
- 这些指标通常被单独分析,限制了对地幔动态的全面理解.
研究的目的:
- 为了整合地震波速度,海洋脊深度和中洋脊基岩组成,以确定地幔温度和组成.
- 调查地幔热量和组成变化的程度和性质.
- 为了建立一个用于地震速度解释的热校准尺度.
主要方法:
- 将地震波速度与海洋山脊深度相关联.
- 分析中洋山脊玄武岩的组成.
- 将综合数据集与地幔温度和组成模型进行比较.
主要成果:
- 观察到的相关性与250°C的温度变化一致,温度变化延伸到超过400公里的深度.
- 结果与常温下地幔组成变化不一致.
- 异常热的山脊段与热点相关,这表明热点火山活动的源头是深层地幔羽毛.
结论:
- 全球存在一个连贯的地幔温度信号,延伸到相当深处.
- 地幔温度变化,而不是构成,是山脊观测到的地震和水位数据的主要驱动因素.
- 这种热信号为解释远离中洋山脊的地区的地震速度提供了关键的校准.
更多相关视频
08:43Separation of Uranium and Thorium for 230Th-U Dating of Submarine Hydrothermal Sulfides
Published on: May 20, 2019
6.2K
11:50Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions
Published on: June 13, 2015
12.0K
相关概念视频
Deep Sea Microbial Ecology
53
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...
53
Global Climate Change
24.4K
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.
24.4K
Diversity of Archaea IV
639
Hyperthermophilic archaea are a group of extremophiles thriving at temperatures above 80°C, often in hydrothermal vents and volcanic soils where conditions surpass the boiling point of water. At such temperatures, proteins, membranes, and DNA in most organisms degrade, but hyperthermophiles have evolved remarkable adaptations to maintain stability and function.Unique Cellular FeaturesHyperthermophilic membranes are composed of a monolayer of biphytanyl tetraether lipids, which resist...
639
Microbial Mats
67
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...
67
Diversity of Archaea III
502
Crenarchaeota, a prominent phylum of Archaea, is remarkable for its ability to thrive in extreme environments characterized by high temperatures and acidity. These microorganisms inhabit sulfuric hot springs, volcanic systems, and submarine hydrothermal vents, where temperatures often exceed 100°C. The unique adaptations of Crenarchaeota not only allow survival under such extreme conditions but also provide insights into the mechanisms of life in primordial Earth-like...
502
Marine Microbial Ecology
66
Marine microbial ecosystems are shaped by distinct physicochemical limits, including high salinity, low nutrient availability, and fluctuating oxygen levels. These conditions favor smaller microbial cell sizes, which maximize their surface-to-volume ratio for efficient nutrient uptake.Microbial activity and community composition are closely linked to biogeochemical cycles, particularly in dynamic environments like estuaries, where halotolerant microbes thrive in response to variable salinity...
66
