Hydrogen in Lower Mantle Minerals: Accomplishment-based Renewal

液态水对生命至关重要，在太阳系内和银河系其他地方寻找宜居行星，归根结底就是寻找可以存在液态水的行星。地球是一颗水行星，但地球是如何获得水的，这是一个激烈的争论、测量、实验和理论计算的主题。目前还没有关于地球上有多少水的固体限制，因为水的成分，氢和氧的原子，被合并到内陆的固体硅酸盐矿物中，这些水可以在很长一段地质时间内与地表水库交换。这是一个实验研究项目，目的是测量氢在地球深处固体氧基硅酸盐矿物中的溶解度，以便对地球在这个占地球质量一半以上的区域可以容纳多少氢施加一些限制。这些可淬火的矿物晶体将在高压和高温下生长，并将测量它们的物理性质(密度和地震速度)。主要目标是限制类地行星内部可以储存的水(氢和氧)的数量，以及这可能如何影响地球内部的动力学。这是一个合成和表征水合硅酸镁和氧化物相的项目，这些相被认为在地球内部600到2900公里深处是稳定的。在与其他研究小组(主要是德国)的合作下，研究人员在含水条件下合成了几种不同晶体结构的硅酸镁样品，其中含有各种少量取代基，主要是铝和铁。他们发现氢在阿莫托石(钛铁矿结构)、镁闪石(石榴石结构)和含铝钙钛矿中有显著的溶解度。本次项目更新的重点是铝钙钛矿中氢的溶解度。镁硅钙钛矿被认为是地球内部最丰富的矿物，也可能是地球上最大的氢储藏库。将对合成的高压矿物进行晶体结构、化学成分和氢含量的分析。为了限制水合作用对地震速度的影响，将进行弹性测量。所获得的数据应该能够更好地理解氢在地幔动力学中的关键作用，并进一步限制可能储存在类地行星内部的氢气量。

Liquid water is essential to life, and the search for habitable planets within our solar system and elsewhere in the galaxy has come down to a search for planets on which liquid water can exist. Earth is a water planet, but how the Earth acquired its water is a subject of intense debate, measurement, experiment, and theoretical calculation. There are not yet solid constraints on how much water the Earth has, because the components of water, atoms of hydrogen and oxygen, are incorporated into the solid silicate minerals of the interior, and this water can be exchanged with the surface reservoir over the long stretch of geologic time. This is an experimental research project to measure the solubility of hydrogen in the solid, oxygen-based silicate minerals of the deep interior of the Earth in order to place some constraint on how much hydrogen the planet can harbor in this region which constitutes more than half the mass of the planet. The mineral crystals, which are quenchable, will be grown at high pressure and temperature, and their physical properties (density and seismic velocity) will be measured. The principal objective is to constrain the amount of water (hydrogen plus oxygen) that can be stored in the interiors of Earth-like planets, and how this may affect the dynamics of the deep interior.This is a project to synthesize and characterize hydrous magnesium silicate and oxide phases thought to be stable in Earth's interior at depths of 600 to 2900 km. In collaboration with other research groups, principally in Germany, the investigators have synthesized samples of MgSiO3 in several different crystal structures under hydrous conditions with various minor substituents, principally aluminum and iron. They have found significant solubility of H in akimotoite (ilmenite-structure), majorite (garnet structure), and in aluminum-bearing perovskite. This project renewal is to focus on H solubility in aluminous perovskite. MgSiO3-perovskite is thought to be the most abundant mineral in the interior and potentially the largest reservoir of H in the planet. Synthesized high pressure minerals will be analyzed for crystal structure, chemical composition and hydrogen content. Measurements of elasticity will be made in order to constrain the effect of hydration on seismic velocity. The data obtained should permit a greater understanding of the crucial role of hydrogen in mantle dynamics and further constrain the amounts of hydrogen that may be stored in the interiors of Earth-like planets.