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

合作研究：俯冲、碰撞和造山，跨越阿拉斯加山脉的宽带地震实验 (BEAAR)

• 批准号: 9725168
• 负责人: Douglas Christensen
• 金额: $ 30.48万
• 依托单位: University of Alaska Fairbanks Campus
• 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: 1998-12-15 至 2003-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9725168&HistoricalAwards=false
• 关键词: Collaborative; Research; Subduction; Collision; Mountain

9725168Christensen 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.***

9725168Christensen这项研究涉及在麦金利山附近的阿拉斯加山脉部署便携式PASSCAL地震仪，以研究俯冲带大型山脉的活动构造和生成过程。 通常提出两大类型的过程：水平挤压，导致地壳增厚和莫霍面偏转支撑山脉，以及动力抬升机制，通过俯冲引起的流动加热岩石圈或抬升岩石圈。 PASSCAL地震测线的台站沿着一条走廊，这条走廊是俯冲板块上典型的造山带，该板块具有北美最高的地形，直接位于100公里深度的板块等高线上，预计可能有弧火山活动。 分析工作将侧重于接收器功能、衰减和旅行时间研究以及剪切波分裂。 结果将与地形和重力观测的质量分布，以检查这些是否足以均衡平衡地形。 这些平衡将第一次显示抬升这里地形和产生地震活动的力量。 这项研究是国家减少地震灾害计划的一个组成部分。