"Silicic magma chambers, explosive volcanism, and a remarkable tectonic control on the ""Earth System"""

我在三个不同的研究领域提出了一个计划。前两者有一个共同的主题，那就是火山爆发，并受到两个问题的推动：1)为什么火山和岩浆室会爆炸？2)有没有严谨可靠的方法来预测对人类有危险的火山活动？从观测的角度来看，解决第一个问题的关键一步是描述具有火山活动历史的岩浆系统的长期行为。然而，构建和理解这样的数据集的一个障碍是，这些系统在数百万年的时间尺度上演变。因此，关键的时间序列数据必须唯一地从保存在化石岩浆室和史前火山碎屑矿床中的结构和化学数据中推断出来，这是具有挑战性的。为此，我们开发了一种严格的基于野外和矿物化学的方法，使我们能够在地质数据中识别关键的岩浆过程，以及它们在喷发前的演化。为了回答第二个问题，我们转向对喷发前地震的实时观测。我们扩展了我们的初步模型，在危险喷发之前预测了这种振荡的特征，也对地震幅度和相关影响，如岩浆气体通量和地面形变进行了可检验的预测。这项工作将为预测爆炸性喷发提供一种新的可靠工具。第三个研究领域探索了一项引人注目的预测的挑衅性含义，即超大陆旋回期间的地幔热制度将导致玄武岩地壳生产实际上停止。地幔(而不是地壳)岩石的大量水化将反过来产生大量甲烷和氢气进入深海。这项工作提出了对海洋化学和生物的长期变异性以及对表面气候的根本构造控制。

I propose a program in three distinct research areas. The first two share a common theme that is explosive volcanism and are motivated by two questions: 1) Why do volcanoes and magma chambers erupt explosively? and, 2) Are there rigorous and reliable ways to forecast volcanism that is dangerous to humans? From an observational perspective, a crucial step towards addressing the first question is to characterize the long-term behavior of magmatic systems that have a history of volcanic activity. A roadblock to building and understanding such a data set, however, is that these systems evolve over million year time scales. Thus, key time series data must be uniquely inferred from textural and chemical data preserved in fossil magma chambers and prehistoric pyroclastic deposits, which is challenging. To this end, we develop a rigorous field- and mineral chemistry-based methodology that enables us to identify key magmatic processes in geological data, as well as their evolution prior to eruption. To address the second question, we turn to real-time observations of pre-eruptive seismic tremors. We extend our preliminary model that predicts the character of this oscillation prior to dangerous eruptions to make testable predictions also for tremor amplitude and related effects such as magmatic gas flux and ground deformation. This work will provide a new reliable tool for forecasting explosive eruptions. The third research area explores provocative implications of a remarkable prediction that the mantle thermal regime during supercontinental cycles will cause basalt crustal production to virtually cease. Extensive hydration of mantle (rather than crustal) rocks will, in turn, produce massive fluxes of methane and hydrogen into the deep ocean. This work proposes a fundamental tectonic control on the long-term variability of the chemistry and biology of the oceans, as well as on surface climate.