权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Collaborative Research: Testing Tectonic Geodesy from Fault Slip Rates Across the Eastern California Shear Zone

合作研究：通过东加州剪切带的断层滑移率测试构造大地测量学

基本信息

批准号：
0337263
负责人：
Michael Oskin
金额：
--
依托单位：
University of North Carolina at Chapel Hill
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2004
资助国家：
美国
起止时间：
2004-01-01 至 2007-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0337263&HistoricalAwards=false
关键词：
Collaborative Research Testing Tectonic Geodesy

项目摘要

The Eastern California Shear zone is an intriguing example of a plate boundary fault system where the known rates of faulting may not add up to the geodetic rate of strain accumulation. This research tests the hypothesis that geologic and geodetic strain rates must somehow agree across the Eastern California Shear zone by gathering new long-term slip rate data from a well-defined, well-exposed, and tectonically simple transect of active faulting across the central Mojave Desert. Field geomorphic and geologic mapping, augmented by targeted acquisition of high-resolution airborne laser swath mapping altimetry data, will document offset Plio-Quaternary lava flows and alluvial fans across each of six right-lateral strike-slip faults. Selected offset markers will be dated with 40Ar/39Ar, cosmogenic 10Be or cosmogenic 3He to measure crustal deformation rates at 10^5 to 10^6 year time scales that average several earthquake cycles. If the geology does account for the geodetic strain rate through significant slip rates on one or more faults, the predictive capability of tectonic geodesy is demonstrated. Alternatively, if the long-term geologic strain rate is significantly slower than the geodetic rate, as seems to be supported by existing paleoseismic data, then a system-wide transient loading process must be responsible for the high present-day strain accumulation across the Eastern California Shear zone.

加州东部的剪切带是板块边界断层系统的一个有趣的例子，在那里，已知的断层速率可能不会与应变累积的大地速率相加。这项研究通过从莫哈韦沙漠中部一条定义明确、暴露良好、构造简单的活动断层断面收集新的长期滑动速率数据，检验了这样一种假设，即地质和大地应变率一定以某种方式在东加州剪切带上一致。实地地貌和地质制图，加上有针对性地获取高分辨率机载激光条带测高数据，将记录六条右行走滑断层中每条断层上的第四纪熔岩流和冲积扇。选定的偏移标记物将用40Ar/39Ar、宇宙成因10Be或宇宙成因3He来测量地壳形变速率，时间尺度为10^5到10^6年，平均几个地震周期。如果地质学确实通过一个或多个断裂上的显著滑动速率来解释大地应变率，则证明了构造大地测量学的预测能力。或者，如果长期地质应变率明显慢于大地应变率，就像现有的古地震数据所支持的那样，那么整个系统范围的瞬时加载过程肯定是横跨东加州剪切带的今天高应变累积的原因。