Two-Phase Damage and the Interactions between Earth's Mantle and Climate: From Plate Tectonic Feedbacks to Carbon Capture

两相损伤以及地幔与气候之间的相互作用：从板块构造反馈到碳捕获

• 批准号: 1015229
• 负责人: David Bercovici
• 金额: $ 37.46万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-15 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1015229&HistoricalAwards=false
• 关键词: Two; Phase; Damage; Interactions; between

The interaction between the Earth's mantle and climate systems occurs through complex processes and over disparate time scales. On the geological time scale, the tectonic cycle buffers CO2 through mountain building and weathering, providing Earth with a temperate climate. The operation of plate tectonics, however, is not impervious to climatic conditions. Although liquid water is thought necessary to lubricate plate tectonics, recent theories postulate that a cool surface promotes lithospheric failure or damage, which then permits plate-like mantle flow on Earth, but not Venus. On human time scales, the rapid efflux of carbon from burning fossil fuels is possibly best mitigated by effectively returning CO2 to the mantle, i.e., by carbon sequestration in mafic and ultramafic rocks. Such processes of mantle-climate interaction, whether natural or man-made, involve multi-phase physics with the additional complexities of chemical reactions, grainsize evolution, and damage mechanics. This proposal is for the PI's on-going work on the development and application of two-phase damage theory; here we propose to address two issues:1. How plate tectonics initiated and plate-boundaries evolve remain unsolved questions in geodynamics, and provide tests of plate generation theories that go beyond modeling instantaneous present-day plate motions. Moreover, such plate-generation questions are possibly linked to climate evolution. If plate generation and a temperate Earth-like climate are mutually required of each other, then there is probably a critical surface temperature at which a planet does or does not achieve a cool/plate-like state, i.e., somewhere between Earth and Venus; this has implications for terrestrial planet evolution both within and outside our own solar system. The timing and vigor of plate initiation on early Earth would also have influenced Archaean climate, estimates of which are highly variable. The formation of new plate boundaries and plate evolution (shrinkage and reorganization) is also associated with climate variation (e.g., by changes in CO2 flux balance, the effect of continental configurations on ocean circulation, weathering, ice-formation, etc.). 2. How can damage enhanced percolation facilitate carbon sequestration in mantle derived rocks? In particular, how are fresh mineral surfaces for carbonate reactions generated by propagating damage fronts during injection of solutions of CO2 in mafic settings? For example, pulses of pressure or porosity waves in these settings would be associated with both void-generating and grainsize-reducing damage that would then enhance CO2 reactivity. These topics bracket the end-member time-scales in mantle-climate interactions. However, the natural long term processes can inform us how to mitigate short-term imbalances. Mitigating anthropogenic CO2 increases without pushing the problem to future generations requires a geologically long-term solution, and is best addressed by mimicking natural carbon buffering by weathering of mantle minerals. This proposal will combine long-term, planetary-scale perspectives with useful approaches to treating the Earth's mantle-climate system.This project is supported by the Geophysics Program and the Office of Cyberinfrastructure's CI-Reuse Venture Fund.

地球地幔与气候系统之间的相互作用是通过复杂的过程和不同的时间尺度发生的。 在地质时间尺度上，构造循环缓冲二氧化碳通过山区建筑和风化，为地球提供温带气候。 然而，板块构造的操作并不是气候条件的不透手。 尽管认为液态水是润滑板构造所必需的，但最近的理论假定凉爽的表面会促进岩石圈的衰竭或损伤，然后允许地球上的板状地幔流，而不可能在金星上进行。 在人类的时间尺度上，碳燃烧化石燃料的快速外流可能是通过有效地返回二氧化碳，即通过在镁铁质和超镁铁质岩石中的碳固存中来减轻碳的快速流出。 这种地幔气候相互作用的过程，无论是自然的还是人造的，都涉及多相物理学，具有化学反应的额外复杂性，晶粒化的进化和损害力学。 该提议是针对PI在开发和应用两相损害理论方面的持续工作；在这里，我们建议解决两个问题：1。板块构造的发起和板束的发展如何在地球动力学中仍未解决，并提供了板板生成理论的测试，这些理论不仅仅是建模瞬时的当前板块运动。 此外，这种板岩生成问题可能与气候进化有关。 如果彼此之间相互需要的板板产生和温带地球状的气候，则行星可能存在或未达到较酷/板状状态的临界表面温度，即地球和金星之间的某个地方；这对我们自己的太阳系内外的地面行星的演变具有影响。 地球早期板启动的时机和活力也将影响古细菌的气候，估计有很大的变化。 新板边界的形成和板的演化（收缩和重组）也与气候变化有关（例如，通过CO2通量平衡的变化，大陆构型对海洋循环，风化，冰层形成等的影响）。 2。如何损害增强的渗滤有助于地幔衍生的岩石中的碳固相？ 特别是，如何在镁铁质环境中注入二氧化碳溶液期间传播损伤方面产生碳酸盐反应的新鲜矿物表面？ 例如，在这些设置中的压力或孔隙率波的脉冲将与空隙生成和换粒损伤有关，从而增强CO2的反应性。 这些主题在地幔气候相互作用中的最终成员时尺度括起来。但是，自然的长期过程可以告知我们如何减轻短期失衡。缓解人为二氧化碳的增加而不将问题推向子孙后代需要地质上的长期解决方案，并且通过模仿天然碳缓冲来解决地幔矿物质来解决。 该提案将将长期的行星规模观点与治疗地球气候系统的有用方法相结合。该项目得到了地球物理计划和Cyber​​infrasture的CI-Reuse Reuse Venture Fund的支持。