Collaborative Research: Simultaneous Imaging of the Megathrust and Volcanic Systems in the Aleutian Islands Using Hybrid Mini Seismic Arrays

合作研究：使用混合微型地震阵列对阿留申群岛的巨型逆冲断层和火山系统进行同步成像

• 批准号: 1358619
• 负责人: Clifford Thurber
• 金额: $ 21.91万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1358619&HistoricalAwards=false
• 关键词: Collaborative; Research; Simultaneous; Imaging; Megathrust

The Alaska-Aleutian subduction zone is one of the most active areas in the world, in terms of its seismic and volcanic activity. The megathrust experiences large damaging fast (normal) earthquakes, slow earthquakes and associated tectonic tremor revealing a wide spectrum of slip behavior. The volcanoes show a complex blend of seismicity, from volcanic tremor to deep long-period (DLP) events. Many of these tectonic and volcanic natural systems remain relatively unexplored because of the challenging logistics leading to poor instrumentation. We propose to install 4 hybrid mini seismic arrays and 6 stand-alone seismic stations on Unalaska and Akutan Islands, to capture this rich variety of seismic activity, both tectonic and volcanic, and image earth structure in high resolution. The experiment is designed such that it simultaneously images multiple sources, thereby illuminating both megathrust and volcanic systems at the same time. Deployment of mini arrays is logistically convenient in this challenging environment compared to conventional network-style deployments with similar number of stations maximizing scientific gain with relatively low cost. This study will be an important step forward in our understanding of the complex volcanic and tectonic systems and their interplay in Alaska-Aleutian subduction complex. This intertwined natural system will be investigated by combining novel array techniques to image multiple sources with an augmented conventional seismic network. This study will examine a wide spectrum of fault slip dynamics, volcanic plumbing system and earth structure in this area. It will not only enrich our knowledge of the subduction system in this area but also might be extrapolated to other areas like Cascadia that are not so productive seismically.The Alaska-Aleutian subduction zone has witnessed a number of large damaging earthquakes in instrumental history. The Unalaska-Akutan area is located near the eastern edge of the 1957 M8.6 megathrust rupture zone. The proposed study will help better understand the dynamics of the subduction fault, and therefore aid in seismic hazard analyses. In addition, Akutan and Makushin are among the most frequently active volcanoes in the United States and are defined as ?very high threat?. They both pose threat to nearby population centers. This study will help us image and understand the volcanic plumbing systems leading to improved monitoring of precursory phenomena. Moreover, this project will help advance the career of an early-career faculty member, post doctoral researchers, and graduate students, and foster collaboration between educational and government institutions.

就其地震和火山活动而言，阿拉斯加 - 亚利亚人的俯冲带是世界上最活跃的地区之一。大型巨星经历了大型破坏（正常）地震，缓慢的地震和相关的构造震颤，揭示了广泛的滑移行为。火山显示了地震性的复杂融合，从火山震颤到深层期（DLP）事件。这些构造和火山天然系统中的许多人仍然相对尚未探索，因为富有挑战性的物流导致仪器不良。我们建议在Unalaska和Akutan群岛上安装4个混合小型地震阵列和6个独立地震站，以捕获这种巨大的地震活动，包括构造和火山，以及高分辨率的图像地球结构。该实验的设计使其同时映像多个来源，从而同时照亮了大型和火山系统。与传统的网络式部署相比，在这个充满挑战的环境中，在逻辑上的部署在逻辑上很方便，其电台数量相似，以相对较低的成本使科学收益最大化。这项研究将是我们对复杂的火山和构造系统的理解及其在阿拉斯加 - 阿拉斯加 - 亚利亚俯冲络合物中的相互作用的重要一步。这种相互交织的自然系统将通过将新型阵列技术与增强的常规地震网络相结合来对多个来源进行图像进行研究。这项研究将检查该区域中广泛的断层滑动动力学，火山管道系统和地球结构。它不仅会丰富我们对这一领域俯冲系统的了解，而且还可以推断出像卡斯卡迪亚这样的其他领域，这些地区并非如此富有成效的地震。 Unalaska-Akutan地区位于1957 M8.6 Megathrust破裂区的东部边缘附近。拟议的研究将有助于更好地了解俯冲断层的动力学，因此有助于进行地震危险分析。此外，Akutan和Makushin是美国最频繁的活火山之一，被定义为“非常高的威胁？”。他们都对附近的人口中心构成威胁。这项研究将有助于我们形象并了解火山管道系统，从而改善对前期现象的监测。此外，该项目将有助于促进早期职业教师，博士研究生和研究生的职业，并促进教育机构和政府机构之间的合作。