Collaborative Research: Delineation of the Slab Geometry of the Cascadia Subduction Zone Using Broadband Teleseismic Waveform Analysis

合作研究：利用宽带远震波形分析描绘卡斯卡迪亚俯冲带的板片几何形状

• 批准号: 8803524
• 负责人: Robert Crosson
• 金额: $ 13.13万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1991-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8803524&HistoricalAwards=false
• 关键词: Collaborative; Research; Delineation; Slab; Geometry

This proposal seeks funding to deploy 7 temporary broadband seismograph stations in a north-south profile at a longitude of about 123oW in western Washington for the purpose of recording teleseismic body waveforms. We intend to undertake a receiver function analysis of the recorded P-waves in order to delineate variations in the amplitude and timing of Ps conversions from the oceanic Moho of the subducted Juan de Fuca plate that are indicative of variations in the geometry of the subducted slab along its strike. Specifically, we will attempt to confirm and refine a working hypothesis recently proposed that suggests that the Juan de Fuca plate may be deformed in a broad arch centered in the vicinity of Puget Sound. This model explains certain aspects of the seismicity beneath this region as well as a number of other geological and geophysical observations. We have recorded teleseismic P-waveforms along an east-west profile at about 47oN latitude that demonstrates that the oceanic Moho of the Juan de Fuca plate has a characteristic signature in teleseismic receiver functions. Results from these earlier deployments are consistent with our arch model. Further refinements in this model will have important implications in terms of the tectonic evolution and earthquake hazards potential of the Cascadia Subduction Zone. This research represents a collaborative project between the University of Missouri-Columbia (T.J. Owens) and the University of Washington (R.S. Crosson).

该提案寻求资金部署7个临时宽带 地震仪站在一个南北剖面上， 在华盛顿西部约123 oW，用于记录 人体波形。 我们打算聘请一名接管人 对记录的P波进行功能分析， 在振幅和时间的变化Ps转换从 Juan de Fuca板块的大洋莫霍面 表明俯冲板片的几何形状变化 沿着它的走向。 具体来说，我们将尝试确认和 完善了最近提出的一个工作假设， 胡安·德富卡板块可能变形为以 普吉特海湾附近 这个模型解释了某些方面 这一地区以及其他一些地区的地震活动 地质和地球物理观测。 我们记录了 沿47 ° N左右东西向剖面沿着的叠加P波 这表明，海洋莫霍面 Juan de Fuca车牌在西班牙语中具有独特的签名 接收器功能 这些早期部署的结果是 与我们的足弓模型一致 对该模型的进一步改进 将对地球的构造 卡斯卡迪亚的演变和地震危险性 俯冲带 这项研究是一个合作项目， 密苏里-哥伦比亚大学（T. J.欧文斯）和密苏里大学 华盛顿（R.S. Crosson）。