Collaborative Research: Determination of Slip Rates on the Death Valley-Fish Lake Valley Fault System: Toward an Understanding of the Spatial & Temporal Extent of Strain Transi

合作研究：死亡谷-鱼湖谷断层系统滑动率的确定：了解空间

• 批准号: 0537901
• 负责人: James Dolan
• 金额: $ 9.3万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0537901&HistoricalAwards=false
• 关键词: Collaborative; Research; Determination; Slip; Rates

The degree to which fault loading and strain release rates are constant (or non-constant) in time and space is one of the most fundamental, unresolved issues in modern geodynamics. Comparisons of short-term geodetic data with very long-term (million year) global plate motion data indicate that, along most plate boundaries, strain storage and release are relatively continuous over a large temporal range. Recent comparisons of geodetic and geologic rate data across the Mojave section of the eastern California shear zone however, point to the occurrence of a pronounced strain transient. These observations raise several fundamentally important questions about how strain accumulates and is released along major plate boundary fault systems. A team of scientists from the University of Southern California, University of Cincinnati, and University of California at Berkeley seeks to understand the spatial and temporal constancy of strain accumulation and release in the northern half of the eastern California shear zone. Specifically, the work will focus on the Death Valley-Fish Lake Valley fault zone, the largest fault system in the region, extending over 300 km from the Garlock fault northward into southwest Nevada. Fault slip rates are being determined at a variety of geologic time scales (1,000 - 100,000 years) along the length of the fault system by dating offset alluvial landforms with cosmogenic nuclide and optically stimulated luminescence geochronology. Deformed geomorphic features are identified, mapped, and restored based on airborne laser swath mapping digital topographic data, acquired in a two-kilometer-wide swath along the fault to allow the research team to determine the geomorphic context of the fault zone and to capture any secondary fault strands or off-fault deformation. Comparison of geologic slip rates determined from the Death Valley-Fish Lake Valley fault zone with short-term geodetic data (decadal) and geologic slip rates from other faults in the region will allow the team to evaluate if the transient strain accumulation observed in the Mojave segment of the eastern California shear zone extends northward as a fundamental feature of the Pacific-North America plate boundary or is alternatively, tied to the zone of structural complexity associated with the Big Bend of the San Andreas fault. The research team will work closely with the U.S. National Park Service in Death Valley National Park to disseminate results of this project to park visitors.

在时间和空间上，故障负载和应变释放率在恒定（或非恒定）的程度上是现代地球动力学中最基本，未解决的问题之一。短期大地测量数据与非常长期（百万年）的全球板运动数据的比较表明，在大多数板界，应变储存和释放相对连续，在较大的时间范围内。然而，最近在加利福尼亚剪切区的莫哈韦段中的大地和地质速率数据进行了比较，但指出发生了明显的应变瞬变。这些观察结果提出了一些关于应变如何积累并沿主要板边界断层系统释放的几个重要问题。来自南加州大学，辛辛那提大学和加利福尼亚大学伯克利分校的科学家团队旨在了解加利福尼亚剪切区北半部的应变积累和释放的空间和时间恒定。具体而言，这项工作将集中在该地区最大的断层系统的死亡谷捕捞湖谷断层区域，从加洛克断层向北延伸至内华达州西南部。通过与宇宙基因核素的冲积和光刺激的发光地球人工学，在断层系统的长度沿多种地质时间尺度（1,000至100,000年）确定断层滑动速率。根据机载激光绘图数字地形数据的数字地形数据，在沿断层的两公里范围内获得的数字地形数据确定，映射和修复了变形的地貌特征，允许研究团队确定任何断层区域的地貌环境并捕获任何次要故障链或越野车变形。比较由死亡山谷湖谷断层区确定的地质滑动速率与该地区其他断层的短期大地测量数据（年代）和地质滑移速率的比较，将使团队能够评估是否在莫哈韦（Mojave）中观察到了瞬态应变的积累加利福尼亚东部剪力区域的细分市场作为太平洋北美板块边界的基本特征向北延伸，或者是与与圣安德烈亚斯断层的大弯相关的结构复杂性区域相关的。研究小组将与死亡谷国家公园的美国国家公园管理局紧密合作，以将该项目的结果传播到公园游客。