Geomechanical and seismological investigations of earthquake processes

地震过程的地质力学和地震学研究

• 批准号: RGPIN-2020-04427
• 负责人: vanderBaan, Mirko
• 金额: $ 5.46万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762601
• 关键词: Geomechanical; seismological; investigations; earthquake; processes

Natural and human-induced seismicity poses a risk to society. It is paramount to have a solid understanding of earthquake physics in order to predict and possibly reduce seismic hazard. This research program combines geomechanical and seismological investigations into earthquake physics. Bonded-particle methods will be used for modeling of the mechanical aspects of earthquake rupture to investigate if systematic relationships exist between stress patterns, event rates, maximum stress drops and the magnitude-frequency distributions. Such relationships will permit to invert for changes in the stress state during earthquake cycles using solely remotely observable measurements. We will also investigate the relative importance of static versus dynamic triggering in both sustaining and creating new rupture using again bonded-particle methods. Both dynamic and static stress perturbations can trigger failure, in particular if the system is close to critically stressed. Understanding their relative importance is thus vital to predict the termination of failure. Furthermore, we will track the full energy budget and thus the exact partitioning into kinetic, potential, fracture energy and frictional losses during rupture to understand the fundamental aspects of rupture but also verify commonly used empirical relationships to estimate stress drops and rupture propagation speeds. Seismological investigations will complement and validate the insights gained from the geomechanical modeling. Because of ongoing research, the applicant has access to industrial datasets where human-induced seismicity occurred during hydraulic fracturing treatments. These datasets will be complemented by publicly available data of both natural and induced seismicity. Furthermore, access to fibre-optic data measuring low-frequency deformation will allow examination of both fast rupture, as emitted by microseismic events, and slow strain deformation, e.g., due to volumetric changes, during fluid injection. This research program will provide training for 11 HQP: 3 BSC, 3 MSc, 2 PhD students and 3 postdocs. HQP will gain pertinent training in geomechanical modeling, observational and theoretical seismology. The outcomes of this research program are expected to benefit society beyond the gained scientific insights and knowledge. An improved understanding of why rupture ends is likely to provide pertinent insights into maximum magnitudes of natural and induced seismicity, which in turn has an immediate impact on seismic hazard assessments. It may also lead to enhanced mitigation strategies to reduce the likelihood of induced seismicity in unconventional oil and gas operations and/or engineered geothermal systems.

自然和人类引起的地震性给社会带来了风险。对地震物理学有牢固的了解，以预测并可能减少地震危害，这是至关重要的。该研究计划结合了地震物理学的地质力学和地震学研究。键合粒子方法将用于建模地震破裂的机械方面，以研究应力模式，事件速率，最大应力下降和幅度频率分布之间是否存在系统关系。这种关系将允许使用仅遥远可观察到的测量值将地震周期期间的应力状态变化。我们还将研究静态触发与动态触发的相对重要性在维持和使用再次键合粒子方法中创建新的破裂。动态压力和静态应力扰动都可能触发故障，特别是如果系统接近急需的压力。因此，了解它们的相对重要性对于预测失败的终止至关重要。 此外，我们将跟踪全部能量预算，从而将精确的分区分解为破裂过程中动力学，潜在的，断裂的能量和摩擦损失，以了解破裂的基本方面，但也验证了常见的经验关系以估计压力下降和破裂的传播速度。 地震学研究将补充并验证从地质力学建模中获得的见解。由于正在进行的研究，申请人可以进入工业数据集，在水力压裂治疗过程中，人类引起的地震性发生。这些数据集将与自然和诱发地震性的公开数据相辅相成。此外，访问测量低频变形的纤维学数据将允许检查快速破裂（通过微作用事件发出）和缓慢的应变变形（例如，由于体积变化，在流体注射过程中）。该研究计划将为11 HQP提供培训：3 BSC，3个MSC，2名博士学位学生和3个博士后。 HQP将获得地质力学建模，观察和理论地震学方面的相关培训。 该研究计划的结果有望使社会受益于获得的科学见解和知识。人们对为什么破裂末端的原因有了深刻的理解，可能会提供有关自然和诱发地震性最大幅度的相关见解，这反过来又对地震危害评估产生了直接的影响。这也可能导致加强缓解策略，以减少非常规石油和天然气运营和/或工程地热系统的诱导地震性的可能性。