3-D Structure and Tectonic Interpretation of the Cascadia Crust and Subducting Slab from SHIPS and Earthquake Data

根据 SHIPS 和地震数据对卡斯卡迪亚地壳和俯冲板的 3-D 结构和构造解释

• 批准号: 0107138
• 负责人: Robert Crosson
• 金额: $ 13.38万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2007-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0107138&HistoricalAwards=false
• 关键词: Structure; Tectonic; Interpretation; Cascadia; Crust

Abstract for proposal EAR 0107138 (PH # 12x)Title: 3-D structure and tectonic interpretation of the Cascadia crust and subducting slab from SHIPS and earthquake dataPI's: Robert S. Crosson, Kenneth Creager University of WashingtonIn the Pacific Northwest, subduction of the Juan de Fuca plate beneath the margin of North America (Cascadia subduction zone) causes earthquakes on the plate boundary, as well as within both the continental crust and the subducting plate (slab). Seismic hazards are of particular concern in western Washington State owing to the concentration of population and earthquakes in this region. The hazard due to earthquakes in the subducting Juan de Fuca slab was underscored by the recent magnitude 6.8 earthquake of February 2001 in the southern Puget Sound region. To make progress in understanding the tectonic processes giving rise to earthquakes in this region, it is necessary to gain a better understanding of the structure of both the crust and upper mantle. Fortunately, recent seismic experiments using controlled sources of energy, such as the SHIPS (Seismic Hazards in Puget Sound) experiment, have provided extensive data which can be used to obtain high resolution images of seismic wave speed in the crust, as well as images of the subducting slab from reflections. In this project, we will combine data from several recent "active source" seismic experiments with extensive earthquake observations from the Pacific Northwest seismograph network (PNSN) to produce a high quality but large-scale model of P wave speed of the crust and upper mantle to a depth of 50-60 km. This model will be used to improve our knowledge of the locations of earthquake recorded by the PNSN, and also to accurately model reflected waves from the subducted slab in order to better understand the origin of slab earthquakes. We plan to provide an internet distribution site for our models and interpretations from this project.

摘要提案编号0107138（PH #12 x）标题：根据SHIPS和地震数据对卡斯卡迪亚地壳和俯冲板的三维结构和构造解释。克罗森，肯尼思·克里格华盛顿大学在太平洋西北部，胡安·德富卡板块在北美边缘（卡斯卡迪亚俯冲带）之下的俯冲在板块边界以及大陆地壳和俯冲板块（板片）内引起地震。由于人口和地震集中在西部华盛顿州，地震灾害特别令人关注。最近2001年2月在普吉湾南部地区发生的6.8级地震突出说明了胡安德富卡板块俯冲带地震造成的危险。为了进一步了解引起该地区地震的构造过程，有必要更好地了解地壳和上地幔的结构。幸运的是，最近使用受控能源的地震实验，如SHIPS（普吉特湾地震灾害）实验，提供了大量的数据，可用于获得地壳中地震波速度的高分辨率图像，以及来自反射的俯冲板的图像。在这个项目中，我们将把最近几次“活动震源”地震实验的联合收割机数据与太平洋西北地震台网（PNSN）的广泛地震观测相结合，以产生一个高质量但大尺度的地壳和上地幔P波速度模型，深度为50-60公里。该模型将用于提高我们对PNSN记录的地震位置的认识，并准确地模拟俯冲板的反射波，以便更好地了解板地震的起源。我们计划为我们的模型和解释提供一个互联网发布网站。