Collaborative Research: Subduction, Collision, and Mountain Building, A Broadband Seismic Experiment Across the Alaska Range (BEAAR)

这项研究包括在靠近麦金利山的阿拉斯加山脉部署便携式pascal地震仪，以研究俯冲带的活动构造和大型山脉的形成过程。通常提出两种主要的过程：一种是水平压缩，它导致地壳增厚，并通过莫霍偏转支撑山脉；另一种是动力隆升机制，它通过俯冲引起的流动加热岩石圈或抬升岩石圈。帕斯卡尔地震台站的地震线沿着一条走廊，这条走廊是北美最高地形的俯冲板块上典型的山地建筑，直接位于100公里深的板块轮廓上，那里可能存在弧火山作用。分析工作将集中在接收函数、衰减和旅行时间研究以及剪切波分裂上。结果将与质量分布的地形和重力观测相结合，以检查这些是否足以平衡地形。这些平衡将首次显示抬升这里地形并产生地震活动的力量。这项研究是国家减少地震危害计划的一个组成部分

9727183Abers This research involves a deployment of portable PASSCAL seismographs across the Alaska Range near Mount McKinley to study the active tectonics and generation process of large mountains at subduction zones. Two broad types of processes are usually proposed: horizontal compression, which results in crustal thickening and support of mountains by Moho deflections, and dynamic uplift mechanisms, which heat the lithosphere or elevate it by subduction-induced flow. The PASSCAL seismic line of stations follows a corridor that typifies mountain building over a subducting slab with North America's highest topography directly over the 100 km depth contour of the slab where arc volcanism might be expected. Analysis efforts will focus on receiver functions, attenuation and travel time studies, and shear-wave splitting. Results will be integrated with topography and gravity observations of mass distributions, in order to examine whether these are sufficient to isostatically balance topography. These balances will show for the first time the forces that elevate topography here and generate earthquake activity. This research is a component of the National Earthquake Hazard Reduction Program.***