Examining the mechanical behavior and evolution of the southern San Andreas fault system through determination of late Quaternary slip rates and distinct element simulations

通过确定晚第四纪滑动速率和不同元素模拟来研究圣安德烈亚斯断层系统南部的力学行为和演化

• 批准号: 1049688
• 负责人: Kimberly Blisniuk
• 金额: $ 8.5万
• 依托单位: Blisniuk Kimberly
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1049688&HistoricalAwards=false
• 关键词: Examining; mechanical; behavior; evolution; southern

Dr. Kimberly Blisniuk has been awarded an NSF Earth Science Post Doctoral Fellowship to carry out a research and education plan at University of California at Berkeley. She will study how deformation within continental strike-slip fault systems is partitioned along and across individual fault strands and fault zones over 1,000s to 100,000s year timescales. More specifically, the project is aimed at understanding the kinematic and mechanical evolution of the San Andreas Fault System in southern California by: (1) mapping offset landforms through wavelet analysis of high-resolution topography data and geologic fieldwork, (2) dating displaced landforms to obtain precise estimates of fault slip rates at multiple time scales by applying terrestrial cosmogenic nuclide exposure age dating of surface clasts and U-series dating of pedogenic carbonate coatings on subsurface clasts, and (3) using those observations to formulate first-order distinct element models simulating the behavior and interactions of faults observed in the field.A particularly promising aspect of this study is that cosmogenic nuclide dating and U-series dating are relatively new dating methods that can be used to reliably date late Quaternary sediments and landforms measurably offset along active faults. Prior to the development of these methods, the dating of fault motion has only been possible at the time scales of geodetic and paleoseismological studies, typically years to thousands of years, or from total displacements of geological units over hundreds of thousands to millions of years. As these new dating techniques permit the dating of fault displacements at time scales of thousands to several hundreds of thousands of years, they provide the "missing link" that existed in geochronologic studies of fault systems. Accordingly, detailed studies of fault systems during this time interval combined with mechanical models that mimic the behavior of faults observed in the field can reveal previously unrecognized aspects of fault mechanics and fault system evolution. Such information can be used to refine and improve models for earthquake recurrence used in assessing seismic hazards. This fellowship will not only develop K. Blisniuk's skills as a researcher but it will also further her skills as an educator through her co-teaching of upper division geology courses and mentoring of undergraduate and graduate students in neotectonic and geochronologic studies at the University of California, Berkeley.

Kimberly Blisniuk 博士获得了美国国家科学基金会地球科学博士后奖学金，以在加州大学伯克利分校开展研究和教育计划。她将研究大陆走滑断层系统内的变形如何在几千到十万年的时间尺度上沿着和跨越各个断层带和断层带进行划分。 更具体地说，该项目旨在通过以下方式了解南加州圣安德烈亚斯断层系统的运动学和机械演化：（1）通过高分辨率地形数据和地质现场工作的小波分析绘制偏移地貌图，（2）通过应用地表碎屑和U系列的陆地宇宙成因核素暴露年龄测年，对位移地貌进行测年，以获得多个时间尺度的断层滑动速率的精确估计 对地下碎屑上的成土碳酸盐涂层进行测年，以及（3）利用这些观测结果制定一阶不同元素模型，模拟在现场观察到的断层的行为和相互作用。这项研究特别有前景的一个方面是宇宙成因核素测年和U系列测年是相对较新的测年方法，可用于可靠地测定晚第四纪沉积物和地貌的年代，这些沉积物和地貌沿着活跃的可测量偏移 缺点。 在这些方法发展之前，断层运动的测年只能在大地测量和古地震学研究的时间尺度上进行，通常是几年到几千年，或者是从几十万到几百万年地质单元的总位移中进行。 由于这些新的测年技术允许在数千年至数十万年的时间尺度上对断层位移进行测年，因此它们提供了断层系统地质年代学研究中存在的“缺失的环节”。 因此，对该时间间隔内的断层系统的详细研究与模拟现场观察到的断层行为的力学模型相结合，可以揭示断层力学和断层系统演化以前未认识到的方面。 此类信息可用于完善和改进用于评估地震灾害的地震复发模型。 该奖学金不仅将培养 K. Blisniuk 作为研究人员的技能，还将通过她在加州大学伯克利分校共同教授高级地质学课程以及指导本科生和研究生进行新构造和地质年代学研究，进一步提高她作为教育工作者的技能。