Numerical Modeling of Earthquake Motions: Waves and Ruptures

点击翻译按钮获取中文摘要

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.