CMG Collaborative Research: Fast Multipole Algorithms for Geophysical Stress Modeling and Their Use in Large-Scale Simulation of Earthquake Occurrence

CMG 协作研究：地球物理应力建模的快速多极算法及其在地震发生大规模模拟中的应用

• 批准号: 0934585
• 负责人: James Dieterich
• 金额: $ 22.04万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0934585&HistoricalAwards=false
• 关键词: CMG; Collaborative; Research; Fast; Multipole; CMG; Collaborative; Research; Fast; Multipole

Fast Multipole Methods (FMMs) are widely used in many branches of science and technology, but there is a need for general-purpose, well-documented open source implementations of optimized versions of the method, suitable for use in the geosciences and other fields. One of the pressing needs for using FMMs is in conducting large-scale mathematical modeling of the occurrence of many earthquakes over a long period of time. Such simulations would produce a synthetic catalog of earthquakes, whose statistical properties, in both space and time, may be similar to the actual distribution of earthquakes that occur in nature. Such simulations are analogous to the global circulation models used by meteorologists and climate scientists to simulate weather and climate. In both cases, the objective is to use basic physical laws to simulate the behavior of a large and complex natural system. We have only recently gained enough knowledge about the complex non-linear geosystem that generates earthquakes that it is possible to conduct realistic earthquake simulations and test them against observed earthquake behavior. It is now possible that the simulations can be sufficiently realistic in detail and large enough in scale that they can be useful in understanding the physics of earthquakes as well as the probabilities of earthquake occurrence, understandings that have important societal benefits. This project will develop FMM algorithms and implement them for use with earthquake simulator codes. These improved codes will also be used to conduct much-improved earthquake simulations. The software we create will be useful for a variety of other applications in science and engineering beyond the one we focus on; we will provide our documented libraries with example problems on an open website and will publicize this to the scientific community.This project will develop, test, and apply new generations of efficient computer programs that can generate hitherto impossible long artificial histories of earthquakes. These histories will enable scientists to understand patterns of occurrence that can be used for estimating the hazard that earthquakes pose to human life and property. For example, the California Earthquake Authority, which sets earthquake insurance rates with billions of dollars of implications for California and the world, presently bases its estimates of the probability of earthquake occurrence on methodology that many experts feel is inadequate. The ability to create computer models that generate many long sequences of earthquakes is regarded by experts as the next important step in improving our understanding of when and where earthquakes may occur in many earthquake prone regions of the USA and abroad. In many ways this approach is similar to the computer-based forecasts of weather and climate that are presently much more advanced than are forecasts of earthquake occurrence. The project involves a new and tight collaboration between mathematicians and earthquake scientists who previously have been developing state-of-the-art approaches in their fields independently. The computer programs that are produced will enhance the ability or society to make fast and efficient computer models with benefits in a range of scientific and engineering applications in addition to their usefulness in understanding earthquakes. The programs will be documented, publicized, and made freely available on a web site.

快速的多极方法（FMM）广泛用于科学和技术的许多分支，但是需要通用，有据可查的该方法的优化版本的通用，文献备受证明的开源实现，适用于地球科学和其他领域。使用FMM的紧迫需求之一是在很长一段时间内进行许多地震发生的大规模数学建模。这样的模拟将产生地震的合成目录，其在时空和时间上的统计特性可能与自然界中发生的地震的实际分布相似。这种模拟类似于气象学家和气候科学家使用的全球循环模型，以模拟天气和气候。在这两种情况下，目标都是使用基本的物理定律来模拟大型自然系统的行为。直到最近，我们才获得了有关复杂的非线性地理系统的足够知识，该系统产生地震，可以进行现实的地震模拟并对观察到的地震行为进行测试。现在，模拟有可能在详细的详细范围内足够现实，并且规模足够大，以便它们有助于理解地震的物理学以及地震发生的概率，以及具有重要社会益处的理解。该项目将开发FMM算法并将其用于地震模拟器代码。这些改进的代码也将用于进行备受改进的地震模拟。我们创建的软件对于超出我们关注的科学和工程的各种其他应用程序将很有用；我们将在开放网站上为有记录的库提供示例问题，并将其向科学界公开。该项目将开发，测试和应用新一代的有效计算机程序，这些程序可能会产生迄今不可能长期的地震人工历史。这些历史将使科学家能够理解发生模式，这些模式可用于估计地震对人类生命和财产的危害。例如，加利福尼亚地震管理局（California Eartquake Authority）设定了地震保险费率，对加利福尼亚和世界的影响数十亿美元，目前基于其对地震发生可能性的估计，这是许多专家认为这是不足的方法。创建产生许多长序列地震序列的计算机模型的能力被专家视为改善我们对美国和国外许多地震易于地震发生何时何地发生地震的理解的下一个重要步骤。在许多方面，这种方法类似于基于计算机的天气和气候预测，这些预测目前比地震发生的预测要高得多。该项目涉及数学家与地震科学家之间的新紧密合作，他们以前独立地在其领域开发了最新的方法。生产的计算机程序将增强其在一系列科学和工程应用中具有好处的快速有效计算机模型的能力或社会，除了它们在理解地震方面的用处。这些程序将在网站上进行记录，宣传和免费提供。