COLLABORATIVE RESEARCH: Geologic and GPS Study: DisplacementPartitioning and Arc-Parallel Extension in the Aleutian Volcanic Island Arc

合作研究：地质和 GPS 研究：阿留申火山岛弧的位移划分和弧平行延伸

• 批准号: 9714887
• 负责人: John Oldow
• 金额: $ 22.24万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-06-01 至 2002-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9714887&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Geologic; GPS; Study

9714887 Oldow In circumstances where the convergence vector between two plates is oblique to the suture, deformation is partitioned into arc-parallel (strike-slip) and arc normal (thrust) components. The parameters controlling this partitioning are not well known, and several models exist. This research in the Aleutian arc takes advantage of a curved suture between plate where the vector varies smoothly from near O (orthogonal) to near 90o (pure strike-slip) to address some of the possible parameters. If the coupling between upper and lower plates remains constant, increasing arc-parallel extension in the upper plate with increasing obliquity should be observed. However, no arc-parallel extension need occur if coupling decreases with increasing obliquity. This project will employ GPS technology to determine translations of the islands along the Aleutian arc and structural analysis to determine operative slip and deformation response. Results should document partitioning of strain with increasing obliquity, identify operative slip mechanisms and allow testing of several hypotheses about partitioning in situation where convergent vectors are oblique to plate margins.

9714887在两个板块之间的会聚向量与缝合线倾斜的情况下，变形被划分为弧形平行(走滑)和弧形法线(逆冲)分量。控制这种划分的参数还不是很清楚，而且存在几种模型。这项关于阿留申弧线的研究利用了板块之间的弧形缝合，其中向量从接近O(正交)到近90度(纯走滑)平滑变化，以解决一些可能的参数。当上、下板之间的耦合保持不变时，随着倾角的增大，上板的弧形平行伸展应逐渐增大。但是，如果耦合随着倾角的增加而减小，则不需要进行弧形平行拉伸。该项目将使用GPS技术来确定阿留申弧线上岛屿的平移，并进行结构分析来确定操作滑动和变形响应。结果应记录随倾角增加的应变分割，确定操作滑动机制，并允许在收敛向量与平板边缘倾斜的情况下检验有关分割的几个假设。