EAR-PF: Dynamic Rupture Modeling on Major San Andreas Fault Intersections

朱利安·C·洛佐斯博士获得了美国国家科学基金会地球科学博士后奖学金，他将在斯坦福大学和美国地质调查局门洛帕克园区开展一项研究和推广计划。这个项目旨在提高我们对物理过程的理解，这些物理过程决定了地震破裂如何协调主要断层之间的交界处，进而提高了我们对断层分段的理解。洛佐斯博士将建立动态破裂模型，为圣安德烈亚斯断层和其他三个断层(分别是圣哈辛托断层、加洛克断层和卡拉维拉斯断层)之间的交界处产生一系列假设地震。这些交汇点中的每一个都代表了不同类型的几何、地质和应力复杂性，并且每个交汇点都对其周围地区构成了重大的地震危险。因此，对圣安德烈亚斯系统的关注将提高对一般断层物理学的理解，以及对加州地震危险的理解。以前的研究集中在这些断层上，或者是对这些连接所代表的几何类型的概括和简化。这项研究将通过将多种类型的复杂性纳入模型输入，对研究领域进行更现实和更详细的建模。复杂的断层几何形状、速度结构和初始应力将通过断层地质学和地震活动性文献以及静态应力模型来了解。一旦情景模拟完成，洛佐斯博士将把模拟结果与古地震和历史数据进行比较，以限制模拟结果与已知的过去断层行为的对比，并提供对这些断层交界处过去地震规模和范围的洞察。许多人居住在研究区域附近，因此，该项目包括一个教育和外展计划，重点是向公众宣传地震的基本科学知识、相关的危险以及如何为之做好准备。洛佐斯博士将在他的研究区域附近的社区进行一系列公开演讲。通过斯坦福大学，他将帮助带领K-12学生到当地断层带进行实地考察，通过美国地质调查局，他将参加更多的公共外联活动。除了向公众宣传，洛佐斯还将协助斯坦福大学开发一门有关断层物理学的研究生课程，这将有助于他为未来在学术界的职业生涯做好准备。

Dr. Julian C. Lozos has been granted a NSF Earth Sciences Postdoctoral Fellowship to carry out a research and outreach plan at Stanford University and the USGS Menlo Park campus. This project aims to improve our understanding of the physical processes that determine how seismic rupture negotiates a junction between major faults, and by extension, our understanding of fault segmentation. Dr. Lozos will conduct dynamic rupture models to produce a suite of scenario earthquakes for the junctions between the San Andreas Fault and three other faults: the San Jacinto Fault, the Garlock Fault, and the Calaveras Fault respectively. Each of these junctions represents different types of geometrical, geological, and stress complexity, and each poses a significant seismic hazard to its surrounding area. Thus, the focus on the San Andreas system will improve understanding of general fault physics, as well as of seismic hazard in California. Previous studies have focused on these faults individually, or on generalizations and simplifications of the types of geometries represented by these junctions. This study will consist of more realistic and detailed modeling of the study areas, by incorporating many types of complexity into the model inputs. Complex fault geometry, velocity structure, and initial stresses will be informed by fault geology and seismicity literature, as well as by static stress modeling. Once the scenario modeling is completed, Dr. Lozos will compare the results to paleoseismic and historical data, both to constrain the modeling results against known past fault behavior, and to provide insight into the sizes and extents of earthquakes at these fault junctions in the past. Many people live in the vicinity of the study areas, and thus, this project includes an education and outreach program focused on informing the public of the basic science of earthquakes, the related hazard, and on how to prepare for them. Dr. Lozos will give a series of public talks in communities near his study areas. Through Stanford, he will help lead field trips for K-12 students to local fault zones, and through the USGS, he will participate in additional public outreach events. In addition to public outreach, Dr. Lozos will also assist in developing a graduate-level course on fault physics at Stanford, which will help prepare him for a future career in academia.