Multiscale seismic imaging of the San-Andreas-Fault system

圣安德烈亚斯断层系统的多尺度地震成像

• 批准号: 65636216
• 负责人: Professor Dr. Stefan Buske
• 金额: --
• 依托单位: Institut für Geophysik und Geoinformatik
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/65636216?language=en
• 关键词: Multiscale; seismic; imaging; San; Andreas

The main objective of project SAFOD (San-Andreas-Fault-Observatory-at-Depth) is to answer fundamental questions about the physical and chemical processes controlling faulting and earthquake generation within a major plate-bounding fault. In that respect significant progress has been achieved recently by acquiring and analyzing various geoscientific data sets. We propose to contribute to this understanding by constructing detailed crustal transects across this plate boundary zone from seismic imaging on different scales. On one hand we want to reprocess existing industry seismic reflection data and USGS seismic refraction data ("SJ6" transect) using innovative seismic imaging techniques (Fresnel-Volume-Migration) in order to map and to analyze its large-scale structural inventory and tectonic environment. We expect that such a reprocessing will resolve in particular the large-scale depth structure and the deep roots of the San-Andreas-Fault system, which has not yet been achieved using recent seismic data sets. On the other hand we want to process microseismic data recorded within the SAFOD borehole, which have illuminated nearby branches of the fault system, using reflection seismic techniques in order to reveal the fine-scale fault structure in the close vicinity of the borehole. These imaging results can be directly used as a calibration tool for seismological investigations as well as borehole studies during the ongoing drilling phase at SAFOD. This multiscale approach will deliver comprehensive seismic images which can be used as a basis for a profound characterization of the subsurface environment and can decisively contribute to the understanding of the seismogenic processes at this major plate bounding fault system.

SAFOD（圣安德烈亚斯断层深度观测站）项目的主要目标是回答有关控制主要板块边界断层内断层活动和地震产生的物理和化学过程的基本问题。在这方面，最近通过获取和分析各种地球科学数据集取得了重大进展。 我们建议通过不同尺度的地震成像构建跨越该板块边界区域的详细地壳横断面，以促进这种理解。一方面，我们希望使用创新的地震成像技术（菲涅耳体积偏移）重新处理现有的工业地震反射数据和 USGS 地震折射数据（“SJ6”横断面），以便绘制和分析其大规模构造清单和构造环境。我们预计这种再处理将特别解决圣安德烈亚斯断层系统的大规模深度结构和深层根源，而使用最近的地震数据集尚未实现这一点。另一方面，我们希望使用反射地震技术处理 SAFOD 钻孔内记录的微震数据，这些数据照亮了断层系统的附近分支，以揭示钻孔附近的精细断层结构。这些成像结果可以直接用作地震调查以及 SAFOD 正在进行的钻井阶段的钻孔研究的校准工具。这种多尺度方法将提供全面的地震图像，这些图像可以作为深入表征地下环境的基础，并且可以为了解这个主要板块边界断层系统的地震发生过程做出决定性贡献。