Spatial Variations in Subduction, Kenai Peninsula, Southern Alaska

该项目将从阿拉斯加南部基奈半岛的新建和现有地点收集全球定位系统（GPS）数据，并使用这些数据来测试俯冲带动力学模型。过去在该地区进行的大地测量工作表明，现今上覆板块的变形沿走向变化很大。相对于（上覆的）北美板块，半岛东部的位置向太平洋-北美板块的相对运动方向移动，而半岛西部的位置则向海沟方向移动，与板块的相对运动方向大致相反。对俯冲带的运动学和动力学有不同含义的许多物理模型可以解释这些结果。为了区分不同的模型，需要更好的数据空间分布和更精确的垂直运动速率。P.I.将包括对水准和潮汐测量数据的仔细分析，以更全面地描述该地区对1964年阿拉斯加大地震的反应，以及它对地震周期模型的影响。

9805326FreymuellerThis project will collect Global Positioning System (GPS) data from new and existing sites on the Kenai Peninsula, southern Alaska, and use those data to test models of subduction zone dynamics. Past geodetic work carried out in this region has shown large along-strike variations in the present-day deformation of the overriding plate. Relative to the (overriding) North American plate, sites in the eastern part of the peninsula move in the direction of relative Pacific-North America plate motion, while sites in the western part of the peninsula move trenchward, roughly opposite to the direction of relative plate motion. A number of physical models, with differing implications for the kinematics and dynamics of the subduction zone, might explain these results. A better spatial distribution of data and more precise vertical motion rates are needed to distinguish between models. The P.I. will include a careful analysis of leveling and tide gauge data to characterize more fully the response to the 1964 Great Alaska earthquake in this region, and its implications for models of the earthquake cycle.