Collaborative Research: San Andreas Scientific Drilling Project: High Resolution Studies of Fault-Zone Process

这项合同是在圣安德烈亚斯断层上钻一个4公里深的洞的全面计划的一个组成部分。钻探地点靠近1966年帕克菲尔德6级地震的震中，圣安德烈亚斯断层在那里滑动，经历了中小地震和无地震蠕变的组合。该项目涉及来自美国和海外的约100名科学家，将与美国地质调查局(USGS)、美国能源部(DoE)和外国机构合作进行。这个特殊的项目涵盖了Parkfield的一个两部分合作和协作的钻探前断层区表征计划的一半。这两个综合的钻井前项目是获取数据的关键路径活动，这些数据将定义大部分井下实验计划。该项目的目标有两个：以足够的准确度和精确度确定钻探目标地震的绝对位置，以确保第二阶段钻探的成功，以及确定断裂带钻探目标体积的小规模(M0，重复次数为几周至几个月)微震活动的系统性(空间-时间-震级)。拟议的协作工作涉及：(A)对现有地震数据进行重新分析；(B)运行一个由15个台站组成的地面“校准”地震台阵；(C)在钻探地点附近安装3个新的钻孔台站；(D)协作分析来自新工作的数据。这些信息将被用来确定钻井计划和工程规格，并优化将在活动断裂带进行的实验。

9814605McEvillyThis award is one component of a comprehensive proposal to drill a 4-km deep hole into the San Andreas fault. The drill site is close to the hypocenter of the 1966 M~6 Parkfield earthquake, where the San Andreas fault slips through a combination of small-to-moderate earthquakes and aseismic creep. The project involves about 100 scientists from the U.S. and abroad and would be conducted in collaboration with the U.S. Geological Survey (USGS), the U.S. Department of Energy (DoE) and foreign institutions. This particular project covers half of a two-part cooperative and collaborative pre-drilling fault-zone characterization program at Parkfield. These two integrated pre-drilling projects are critical-path activities to acquire data that will define much of the downhole experimental program. The goals of the project are twofold: to determine the absolute locations of the drilling target earthquakes with sufficient accuracy and precision to assure a successful second stage of drilling, and to define systematics (space-time-magnitude) in microseismicity at small-scale (M0, recurrence times of weeks to months) in the drilling target volume of the fault zone. The proposed collaborative work involves (a) reanalysis of existing seismic data, (b) operation of a 15-station surface "calibration" seismic array, (c) installation of 3 new borehole stations near the drilling site, and (d) collaborative analysis of data from the new efforts. This information will be used to determine the drilling plan and engineering specifications for the hole, and to optimize the experiments to be conducted in the active fault zone.