Integrating geodesy, seismology and dynamic rupture modeling: the 2010 Sierra El Mayor-Cucapah earthquake

研究人员建议生成2010年4月4日在北方下加利福尼亚发生的不寻常的MW 7.2 Sierra El Mayor-Cucapah #8208;#8209;地震的综合模型。对这次地震进行了许多新的观察？的行为，包括破裂的断层段之间的多个映射步距，目击者报告的局部反向破裂方向，加上地震有一个更大的破裂长度（~100公里）比通常看到的事件的规模。我们将以两种方式对地震进行建模：第一，采用运动学逆模型，该模型结合了所有可用的观测数据（例如，干涉合成孔径雷达、全球定位系统、地震波形、强震波形、地质破裂数据），以便生成所涉及断层段的真实地下几何形状，以及地震破裂期间这些断层上的滑动如何演变的图片。这将使用由PI开发的基于贝叶斯最大似然估计的方法来实现。第二，他们将使用三维有限元代码生成正向动态地震破裂模型，该代码试图通过改变初始物理条件（例如，地震前的#8208;#8209;地震应力和摩擦条件）来再现运动学模型和目击者所看到的特征。最终的结果将是对地震如何以及为什么破裂的完整描述。将如此多的专业知识整合到一个单一的地震研究中以前从未尝试过。我们将获得更多关于地震过程的见解，而不是孤立地应用任何单独的技术。此外，对地震所涉及的断层作用的详细描述将有助于我们评估其对附近加州南部活动断层的潜在影响？埃尔西诺和圣哈辛托断层，从而帮助该地区的地震灾害评估。除了通过会议和出版物传播研究结果，研究人员的目标是通过开发英语和西班牙语的博物馆展品在加州大学滨江和其他地方展出，向公众传达我们的研究结果。

The researchers propose to generate comprehensive models of the unusual April 4th, 2010 Mw 7.2 Sierra El Mayor-­‐‑Cucapah earthquake in northern Baja California. A number ofnovel observations were made of this earthquake?s behavior, including multiplemapped stepovers between ruptured fault segments, eyewitness reports of locallyreversed rupture direction, plus the earthquake had a greater rupture length (~100 km) than is typically seen for an event of its size. We will model the event in two ways: first, with a kinematic inverse model that incorporates all available observational data (e.g. InSAR, GPS, teleseismic waveforms, strong motion waveforms, geologic rupture data) in order to generate both realistic subsurface geometries of the fault segments involved, and a picture of how the slip evolved on those faults during the earthquake rupture. This will be achieved using a Bayesian maximum likelihood-­‐‑based method developed by the PI. Second, they will produce forward dynamic earthquake rupture models using a 3D finite element code that seek to reproduce the features seen in the kinematic model and by eyewitnesses, by varying the initial physical conditions (e.g. pre-­‐‑earthquakestresses and frictional conditions.) The end result will be a full description of both how and why the earthquake ruptured.The incorporation of such a diverse range of expertise into asingle earthquake study has not been attempted before. We stand to gain more insights into the earthquake process than would be possible from applying any of the individual techniques in isolation. In addition, a detailed description of the faulting involved in the earthquake will help us to evaluate its potential effects on the nearby active faults in southern California ? the Elsinore and San Jacinto faults, and thus aid seismic hazard assessments in the region.In addition to disseminating findings through conferences and publications,the researchers aim to communicate our findings to the public by developing museum exhibits in both English and Spanish for display at UC Riverside and elsewhere.