EAR-PF: Adjoint Tomography, Seismic Hazard, and Active Tectonics of the San Joaquin Basin, California

卡尔·塔普博士被授予美国国家科学基金会地球科学博士后奖学金，在哈佛大学开展一项研究和教育计划。他将构建圣华金盆地及其邻近地区的三维结构模型。将根据地震速度变化、密度变化以及主要地质界面的几何形状(如盆地边界和断层)来描述盆地。调查将包括三个阶段。首先，利用工业测井和地震反射资料建立盆地模型。其次，将使用超级计算集群对该地区以前记录的地震进行数值模拟。第三，盆地模型将通过一种称为伴随层析成像的程序，利用数值模拟的结果进行迭代改进。由此产生的三维结构将在当地活动构造的背景下进行解释，例如邻近内华达山脉的分层。地震模拟的结果将用于评估圣华金盆地的地震危险性。大谷位于内华达山脉以西，海岸山脉以东。它是美国最大的农业生产国，也是主要的石油生产国，人口超过650万。山谷的南部，圣华金盆地，充满了几公里的沉积物，这使得山谷在地震期间容易发生增强和长期的震动。该地区被活动断层包围，包括西边的圣安德烈亚斯断层和南边的白狼和加洛克断层。该盆地是南加州最突出的构造特征之一，但其结构和地震响应尚不为人所知。地震灾害和活动构造的结果将传达给圣华金盆地的社区，重点是人口最多、地震风险最大的贝克尔斯菲尔德。

Dr. Carl Tape is awarded an NSF Earth Science Postdoctoral Fellowship to carry out a program of research and education at Harvard University. He will construct a three-dimensional structure model of the San Joaquin basin and adjacent regions. The basin will be described in terms of seismic velocity variations, density variations, and geometries of the major geologic interfaces, such as basin boundaries and faults. The investigation will consist of three stages. First, a basin model will be constructed using industry well logs and seismic reflection data. Second, numerical simulations of previously recorded earthquakes in the region will be performed using supercomputing clusters. Third, the basin model will be iteratively improved using the results of the numerical simulations in a procedure known as adjoint tomography. The resultant three-dimensional structure will be interpreted in the context of the local active tectonics, such as the delamination of the adjacent Sierra Nevada. Results from the earthquake simulations will be used to assess the seismic hazard in the San Joaquin basin.The Great Valley lies west of the Sierra Nevada and east of the Coast Ranges. It is the largest agricultural producer in the United States, a major oil producer, and home to more than 6.5 million people. The southern portion of the valley, the San Joaquin basin, is filled with several kilometers of sediment that makes the valley prone to enhanced and prolonged shaking during earthquakes. The region is surrounded by active faults, including the San Andreas fault to the west and the White Wolf and Garlock faults to the south. The basin is one of the most prominent tectonic features in southern California, yet its structure and seismic response are not well known. The findings of both the seismic hazard and the active tectonics will be conveyed to the communities of the San Joaquin basin, with emphasis on Bakersfield, which has the largest population and greatest seismic risk.