Geofluids and Geohazards

拟议的研究计划将为卡尔加里大学一个新的“地球流体”跨学科研究小组提供基础，该小组最初将集中于量化流体和流体压力在俯冲带地震活动和海底滑坡中的作用，使用地壳尺度的流体流动模型。升高的流体压力被认为是造成这两种危险的一种机制：通过机械地削弱斜坡沉积物，并“预先调节”它们在地震中失效，以及通过降低俯冲带板块边界断层的有效应力和摩擦特性。模型开发和参数化将成为HQP项目的基础，硕士学生主要关注通过分析地球物理数据（即热流和地震反射数据）和通过海洋钻探回收的岩心的实验室变形实验（即孔隙度和渗透率）来约束模型参数。博士生将负责将这些数据集综合到流体流动模型中，并进行用于预测每个研究区域压力分布的模拟。该研究计划的第一个项目将集中在现有合作的重点地区：新西兰的Hikurangi俯冲带和加利福尼亚州的圣巴巴拉盆地。

The proposed research program will provide the foundation for a new interdisciplinary research group in “Geofluids” at the University of Calgary, which will initially focus on quantifying the role of fluids and fluid pressures in subduction zone seismicity, and submarine landslides, using crustal scale models of fluid flow. Elevated fluid pressures have been invoked as a mechanism in both of these hazards: by mechanically weakening slope sediments, and “preconditioning” them to fail in an earthquake, and by reducing the effective stress and frictional properties of the plate boundary fault in subduction zones. The model development and parameterization will form the basis for HQP projects, with M.Sc. students primarily focused on constraining model parameters through analysis of geophysical data (i.e. heat flow and seismic reflection data), and laboratory deformation experiments on cores recovered through ocean drilling (i.e. porosity and permeability). Ph.D. students will take responsibility for synthesizing these datasets into the fluid flow model, and conducting the simulations used to predict the pressure distribution in each study area. The first projects in the research program will concentrate on regions that are the focus of existing collaborations: the Hikurangi subduction zone, New Zealand, and the Santa Barbara Basin, California. Both shallow earthquakes and submarine landslides have the potential to generate tsunamis, which highlights the need to understand these systems as a first step toward assessing potential hazards, particularly in highly populated coastal areas. The work proposed here will fundamentally advance the study of both these hazards by bridging the gap between the geophysical observations linked to fluid pressures (e.g. seismological, geodetic, temperature, pressure data) and the fundamental processes that govern the production and movement of submarine fluids in coastal, hazard prone regions. The long-term results of this program will be a robust workflow that can be applied to a broad range of marine and terrestrial projects that require a broad interdisciplinary approach, including induced seismicity and terrestrial landslides, which have also invoked fluid pressures as a primary causative mechanism. The model results for the study in Southern California will inform future studies aimed at investigating the potential of tsunamogenic landslides in other basins, with a focus on Canada's seismically active West Coast.