Sampling the intermediate loop of the subduction factory at Nankai: The mud volcanoes of the Kumano Basin, Japan

2011年重创日本的大地震起源于太平洋岛国以西的俯冲带。断裂带上流体的存在和多次被困在岩石中有助于润滑滑动，或者当受到压力时，导致地壳超压和破裂，导致断层运动和地震。了解形成俯冲带岸边的吸积楔中流体的来源可以帮助我们更好地了解断层和地震动力学。这项研究涉及测量南开俯冲带(NantroseIZE)一个主要国际计划(Nantroseize)区域内泥火山发出的流体通量的速率，该计划正在研究与滑动有关的断层和变形。这笔资金使一名美国科学家能够参加一次国际海洋巡航，在那里，他的流体计将被部署，以收集一组时间序列的流体样本，供以后在实验室进行地球化学分析。此外，将采用岩心来研究沉积物和相关的孔隙水。来自这两个装置的样本将被分析出各种关键化学元素和特征，这些元素和特征将阐明流体的来源以及泥火山和沉积物中正在进行的化学反应。该项目的更广泛影响包括增加我们对大地震可能触发因素的了解，对早期职业调查员的支持，利用船只时间而不向NSF支付任何费用，与德国和日本科学家进行国际合作，以及通过当地水族馆进行公众宣传。公众宣传活动包括科学家和水族馆工作人员之间的互动以及为K-12学生编写学习材料。在劳动力培训方面，将涉及一名研究生和本科生。

The major 2011 earthquake that devastated Japan has its origins in the subduction zone just west of the island in the Pacific Ocean. The presence of fluids on fault zones and trapped in rocks many times helps to lubricate slip or, when under stress, cause overpressuring and fracturing of the crust, resulting in fault motion and earthquakes. Knowing the origin of fluids in accretionary wedges that form just shoreward of subduction zones can help us better understand fault and earthquake dynamics. This research involves measuring the rate of fluid fluxes emanating from mud volcanoes in the area of a major international program that is studying the faulting and deformation associated with slip in the Nankai subduction zone (NanTroSEIZE). This funding allows a US scientist to participate in an international oceanographic cruise where his fluid meters will be deployed to collect a time-series set of fluid samples for later geochemical analysis in the laboratory. In addition cores will be taken to allow the study of sediments and associated pore waters. Samples from both devices will be analyzed for various key chemical elements and signatures that will illuminate the source of fluids and the chemical reactions going on in the mud volcanoes and sediments. The broader impacts of this project include increasing our knowledge of possible triggers of major earthquakes, support of an early career investigator, leveraging of ship time at no cost to NSF, international collaboration with German and Japanese scientists, and public outreach through a local aquarium. Public outreach activities include the interaction of scientists and aquarium staff and the development of learning materials for K-12 students. In terms of workforce training, a graduate student and undergraduates will be involved.