CAREER: Investigating Earthquake Cycles on Mid-Ocean Ridge Transform Faults

职业：研究大洋中脊转换断层的地震周期

• 批准号: 1352565
• 负责人: Margaret Boettcher
• 金额: $ 42.66万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-15 至 2021-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1352565&HistoricalAwards=false
• 关键词: CAREER; Investigating; Earthquake; Cycles; Mid

Seismicity on mid-ocean ridge transform faults (RTFs) is remarkably systematic and this study will explore the physical reasons for this unusual predictability in earthquake behavior. Transform fault length and plate tectonic slip rate are the basis of global scaling relations that robustly estimate the size of the largest earthquake, the seismic coupling, and the repeat time of the largest earthquakes on most RTFs. However, the processes that create this regularity in RTF seismic cycles and that limit the size of their largest earthquakes are unknown. This integrated research and education project comprises two main components: A comprehensive analysis of RTF structure from high-resolution multibeam bathymetry and finite element modeling of RTFs; Derivation of earthquake source parameters on typical (Gofar) and atypical (Clipperton) RTFs to compare along strike variation in seismic coupling and fault properties. The ultimate aim of this project is to improve seismic hazard assessment by determining if time-dependent hazard models, which describe hazard as being low following a large earthquake and building with time, actually reflect the underlying mechanics of fault slip on geometrically simple faults. Part of the study will be completed through undergraduate class projects, with students trained in the use of geophysical datasets and resources. Two graduate students will gain research experience. Basic concepts on earthquake generation and predictability will be conveyed to high school physics teachers through simple analog experiments that are one component of a new professional development workshop. High school physics curricula will be developed as an outcome of the Summer workshops, and university students will gain educational experience working in the classroom with the teachers throughout the following school year.

洋中脊转换断层（RTFs）上的地震活动性是非常系统的，本研究将探讨地震行为中这种不寻常的可预测性的物理原因。变换断层长度和板块构造滑动速率是全球尺度关系的基础，该关系稳健地估计了大多数rtf上最大地震的大小、地震耦合和最大地震的重复时间。然而，在RTF地震周期中产生这种规律性的过程以及限制其最大地震规模的过程尚不清楚。这个综合研究和教育项目包括两个主要部分：通过高分辨率多波束测深和RTF有限元建模对RTF结构进行全面分析；推导典型（Gofar）和非典型（Clipperton） rtf的震源参数，比较地震耦合和断层性质沿走向的变化。该项目的最终目的是通过确定时间相关的风险模型（描述大地震发生后的危险性较低，并随着时间的推移而建造）是否实际上反映了几何上简单断层滑动的潜在机制，从而改进地震风险评估。部分研究将通过本科课程项目完成，学生将接受地球物理数据集和资源使用方面的培训。两名研究生将获得研究经验。地震发生和可预测性的基本概念将通过简单的模拟实验传达给高中物理教师，这是一个新的专业发展研讨会的一个组成部分。作为暑期讲习班的成果，高中物理课程将被开发，大学生将在下一学年与老师一起在课堂上获得教育经验。

项目成果

The relationship between seismicity and fault structure on the Discovery transform fault, East Pacific Rise

东太平洋海隆发现转换断层地震活动与断层结构之间的关系

• DOI: 10.1002/2014gc005445
• 发表时间: 2014
• 期刊: Geosystems
• 作者: Wolfson-Schwehr, Monica;Boettcher, Margaret S.;McGuire, Jeffrey J.;Collins, John A.
• 通讯作者: Collins, John A.