MARGINS/GeoPRISMS Post-Doctoral Fellowship Research: Evolution of Sediment Physical Properties in the Nankai Subduction Zone and Implications for the Updip Limit of Seismogenesis

摘要：通过实验方法，结合地震资料和微观结构观测，为俯冲系统变形和滑动行为的博士后研究提供了资金。PIs将在高温下对蒙脱石和伊利石进行摩擦实验，并测量不同应力状态下沉积物岩心样品上的声波速度。摩擦实验的结果将用于进一步验证蒙脱石-伊利石过渡的地震活动上倾极限假设。不同应力状态下的声波速度的测量将允许pi通过结合地震数据来估计俯冲系统的地应力状态和孔隙压力。来自IODP NanTroSEIZE样带区域的样品和数据将用于研究原位应力和孔隙压力条件。更广泛的影响该奖项将支持一名年轻的女性研究员作为边际/地球地质科学研究所的博士后研究员。本研究旨在了解孕震带上限滑动行为的演化以及俯冲带断裂系统和增生棱镜的变形机制。拟议研究的重点也与新地质系统项目中俯冲旋回和变形倡议的关键问题一致。了解俯冲板块边界断裂变形的机理和现场条件，在地震预报和防灾方面具有重要的科学意义和社会意义。

Abstract Funds are provided for a post-doctoral study of deformation and slip behaviors in subduction systems by an experimental approach combined with seismic data and microstructure observations. The PIs will conduct friction experiments on smectite and illite at elevated temperature and measure the acoustic wave velocities on sediment core samples at different stress states. Results of the friction experiments will be used to further test the hypothesis of smectite-illite transition for updip limits of seismicity. The measurements of acoustic wave velocities at different stress states will allow the PIs to estimate the in-situ stress states and pore pressure in subduction systems by incorporating with seismic data. Samples and data from the IODP NanTroSEIZE transect area will be used to investigate the in situ stress and pore pressure conditions. Broader ImpactsThe award will support a young female researcher as a MARGINS/GeoPRISMS postdoctoral fellow. The proposed research aims to understand the evolution of slip behavior at the upper limit of the seismogenic zone and the deformation mechanisms in subduction zone fault systems and accretionary prisms. The focal points of the proposed study are also aligned with key questions of the Subduction Cycles and Deformation initiative within the new GeoPRISMS program. Understanding the mechanics and in situ conditions of faulting deformation at subduction plate boundaries has both scientific and social significance in terms of earthquake prediction and disaster prevention.