Collaborative Research: Laboratory and Theoretical Investigations of the Micro-Mechanical Origins of Rate and State Friction on Tectonic Faults

合作研究：构造断层上速率和状态摩擦的微机械起源的实验室和理论研究

• 批准号: 1547441
• 负责人: Chris Marone
• 金额: $ 30.5万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-01 至 2020-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1547441&HistoricalAwards=false
• 关键词: Collaborative; Research; Laboratory; Theoretical; Investigations

In the earthquake-cycle, tectonic faults slowly accumulate stress, due to plate tectonic motion of Earth?s surface, and then fail catastrophically in earthquakes. One of the keys to simulating the earthquake cycle are friction laws that can be applied to both the fast, dynamic motion of earthquakes, as fault rocks rub and slide past one another in frictional contact, and the slow processes of stress accumulation between earthquakes that can take hundreds of years. In this collaborative work between Princeton and Penn State Universities, unusually well-controlled measurements of frictional sliding will be conducted while collecting simultaneous ultrasonic data on the sliding interfaces and sheared layers of fault gouge. The proposed work has important societal implications for seismic hazard assessment, earthquake forecasting, and an improved, fundamental understanding of earthquake nucleation.Rate-and-state friction laws represent the current state-of-the-art in the laboratory and for numerical simulations of earthquake physics, including nucleation, dynamic rupture and the complete seismic cycle. However, our understanding of friction memory effects and slip velocity dependence remains primarily empirical, which limits our ability to apply laboratory measurements to earthquake faults and/or to address the problems associated with predicting the behavior of tectonic faults from laboratory measurements. To address these shortcomings, recent advances in ultrasonic monitoring of sliding rock surfaces and sheared granular fault gouge will provide fundamental insights into the physics and micro-mechanical origins of frictional behavior of tectonic faults.

在地震周期中，由于地球表面的板块构造运动，构造断层逐渐累积了应力，然后在地震中灾难性地发生灾难性。 模拟地震循环的关键之一是摩擦定律，可以应用于地震的快速动态运动，因为断层岩石在摩擦接触中摩擦并互相滑动，以及在地震之间的压力缓慢，这可能需要数百年的时间。在普林斯顿大学和宾夕法尼亚州立大学之间的合作工作中，将在收集滑动接口和断层式剪切层的同时超声数据时进行摩擦滑动的异常控制测量。拟议的工作对地震危险评估，地震预测以及对地震成核的基本理解具有重要的社会影响。Rate-and-and-STATE摩擦法代表了实验室中的当前现状以及地震物理学的数值模拟，包括核损坏，动态破裂，完全的地震循环。 但是，我们对摩擦记忆效应和滑动速度依赖性的理解仍然主要是经验，这限制了我们将实验室测量的能力应用于地震断层和/或解决与预测实验室测量的构造断层行为相关的问题。 为了解决这些缺点，对滑动岩石表面和剪切的颗粒断层的超声监测的最新进展将提供对构造断层摩擦行为的物理和微机械起源的基本见解。