RAPID: Short-period Seismic Study of Actively Serpentinizing Lithosphere in the Oman Ophiolite

流体与富镁和贫硅岩石的相互作用导致化学反应，从流体中去除二氧化碳。这已经被提议作为碳封存的一种手段。世界上最大的此类岩石体位于阿曼，NSF资助了一项钻探计划，以评估流体-岩石相互作用的机制和化学性质。在两个钻孔中部署了水听器阵列，以测量与这种相互作用有关的裂缝。初步数据显示，裂缝的频率高得出乎意料，而且还会随着钻孔产生驻波，这是一种管风琴效应。RAPID的提议是现在在孔洞周围部署一个密集的地震仪网络，以便定位裂缝，测量裂缝如何打开，并测量孔洞周围的速度结构。与阿曼的科学家进行了实质性的合作。一个短周期地震仪网络将部署在阿曼蛇绿岩的一个装有水听器的ICDP孔周围。在部署水听器期间获得的数据显示，水柱中地震活动性和驻波的产生出乎意料地高。这个阵列将允许精确定位每小时发生10次的事件和震源机制。此外，驻波可以作为地幔剖面成像的震源。阿曼项目背后的动机是测试超镁质岩石中碳封存的可行性。该项目涉及实质性的国际合作。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Interaction of fluids with magnesium-rich and silicon-poor rocks results in chemical reactions that remove carbon dioxide from the fluids. This has been proposed as a means of carbon sequestration. The world's largest body of such rocks occurs in Oman, and NSF has funded a drilling program to assess the mechanisms and chemistry of fluid-rock interaction. A hydrophone array was deployed in two of the drill holes to measure cracking related to this interaction. Preliminary data show an unanticipated high frequency of cracking, which also produces standing waves with the drill hole, an organ-pipe effect. This RAPID proposal is to now deploy a dense network of seismometers around the holes, in order to locate the cracking, measure how the cracks open, and measure the velocity structure around the holes. There is substantive collaboration with scientists from Oman.A network of short-period seismometers will be deployed around a hydrophone-instrumented ICDP hole in the Oman ophiolite. Data obtained during deployment of the hydrophones show unexpectedly high amounts of seismicity and the production of acoustic standing waves in the water column. This array will permit accurate location of the events, which occur at a rate of about 10 per hour, and focal mechanisms. Moreover, the standing waves can be used as a source to image the mantle section. The motivation behind the Oman project is to test the feasibility of carbon sequestration in ultramafic rocks. The project involves substantive international collaboration.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.