Numerical Modeling of Earthquake Motions: Waves and Ruptures

地震运动的数值模拟：波浪和破裂

• 批准号: 1449275
• 负责人: Ralph Archuleta
• 金额: $ 3.8万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1449275&HistoricalAwards=false
• 关键词: Numerical; Modeling; Earthquake; Motions; Waves

NSF support for ?Numerical modeling of earthquake motions: waves and ruptures? will allow scientists, particularly those who are students and early career, to communicate their results with researchers from Asia and Europe who use numerical simulations to investigate earthquake rupture processes and wave propagation. Simulated ground motions are being used to guide the development of ground motion prediction equations?the basic tool used in earthquake engineering design as well as seismic hazard maps. This workshop will focus on the most recent research concerning our understanding of the earthquake rupture and the effect of the Earth?s structure on the radiated seismic waves that result in the shaking that is experienced during an earthquake. The four-day workshop combines oral presentations and posters that highlight the most recent developments in numerical simulations of earthquakes, constitutive laws for friction and wave propagation in complex media.Numerical simulation of rupture propagation and seismic waves is an essential tool for investigating earthquake physics and refining the velocity structure of the Earth. The physics of earthquake ruptures is a complex phenomenon involving the constitutive law for sliding friction (with many different processes, e.g., temperature, pressure, slip and slip rate, affecting the friction) along with a medium that may behave elastically or plastically. The fault itself has an inherent roughness at all scales. There is simply too few data by which one can constrain the physics of an earthquake rupture. The earthquake rupture, being complex, produces a complex radiated field which is poorly sampled by the arrays of seismic instruments. Because one cannot directly observe an earthquake ? the complex evolution of slip on a fault, which is buried within the Earth to depths of 100?s of kilometers ? a primary question is what data can constrain the numerical models? Thus the participants in the workshop will be considering both forward modeling of earthquakes and inversion methods by which properties of the earthquake source are inferred. The approaches are complementary; both depend on the elastic and attenuation properties of the Earth. Because of uncertainties in the properties of the Earth as well as the spatial-temporal distribution of stresses on the fault, there are tradeoffs between what is considered a property of the source and what is a property of the Earth. The discussion in a focused workshop allows those who have experience with these problems to discuss how the different methods might lead to better constraints on the source and propagation. This would lead to better numerical simulations and hence more realistic ground motion estimates from future earthquakes.

NSF支持？地震运动的数值模拟：波和破裂？将允许科学家，特别是那些谁是学生和早期的职业生涯，交流他们的结果与来自亚洲和欧洲的研究人员谁使用数值模拟来调查地震破裂过程和波传播。模拟地面运动正被用来指导地面运动预测方程的发展？地震工程设计中使用的基本工具以及地震危险性图。本次研讨会将集中在最新的研究有关我们的理解地震破裂和地球的影响？在地震中产生震动的辐射地震波上的结构。这次为期四天的研讨会结合了口头报告和海报，重点介绍了地震数值模拟的最新进展，复杂介质中摩擦和波传播的本构律，破裂传播和地震波的数值模拟是研究地震物理和改进地球速度结构的重要工具。地震破裂的物理学是一个复杂的现象，涉及滑动摩擦的本构律（具有许多不同的过程，例如，温度、压力、滑动和滑动速率，影响摩擦）沿着可表现为弹性或塑性的介质。断层本身在所有尺度上都具有固有的粗糙度。人们可以用来限制地震破裂物理学的数据实在太少了。地震破裂是复杂的，产生复杂的辐射场，地震仪器阵列对该辐射场的采样很差。因为我们无法直接观测到地震。断层滑动的复杂演化，它埋在地球内部100？s公里？一个主要的问题是什么数据可以约束数值模型？因此，讲习班的与会者将考虑地震的正演模拟和推断震源性质的反演方法。这两种方法是互补的;两者都取决于地球的弹性和衰减特性。由于地球性质的不确定性以及断层上应力的时空分布，在被认为是震源性质和地球性质之间存在权衡。在专题研讨会上进行的讨论使那些有经验的人能够讨论不同的方法如何更好地约束源和传播。这将导致更好的数值模拟，从而更现实的地面运动估计未来的地震。