Reflections Under the Scottish Highlands (RUSH II): A Broadband Investigation of the Extent and Origin of Upper Mantle Reflectors in Scotland

苏格兰高地下的反射（RUSH II）：对苏格兰上地幔反射器的范围和起源进行宽带调查

• 批准号: 0074002
• 负责人: James Knapp
• 金额: $ 28.5万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0074002&HistoricalAwards=false
• 关键词: Reflections; Under; Scottish; Highlands; RUSH

James H. KnappEAR-0074002Upper mantle reflections beneath the northwestern British Isles are some of the best-known and most-studied examples of fine-scale heterogeneity within the mantle. First observed on BIRPS marine deep seismic reflection profiles, these reflectors have subsequently been imaged and correlated on additional reflection and refraction profiles in the offshore area of northern and western Scotland, but have not been reliably traced beneath the mainland, although analysis of existing wide-angle reflection data suggest these reflectors do project beneath mainland Scotland. The present study will address both the scientific potential of broadband imaging of fine-scale upper mantle structure as well as the tectonic significance of major mantle reflectors beneath the British Isles. The project will support a 2-year deployment of a 25-station broadband seismic network in Scotland to perform the following tasks. 1) Correlate the seismic signature of upper mantle reflectors on passive- and active-source records. 2) Determine the regional extent of mantle reflectors beneath the Scottish mainland. 3) Examine the geometric relationship of upper mantle reflectors with lithosphere-scale structures of Paleozoic age. 4) Estimate the physical properties, including anisotropy, of these reflectors and their surrounding lithospheric mantle. 5) Test the hypothesis that upper mantle structure is largely Cenozoic in age. This effort will leverage NSF funds with existing support from the British NERC to the University of Bristol for phase I of the RUSH experiment.

不列颠群岛西北部的上地幔反射是地幔内部精细尺度非均质性的一些最著名和研究最多的例子。首先在BIRPS海洋深层地震反射剖面上观察到这些反射体，随后在苏格兰北部和西部近海地区的其他反射和折射剖面上对这些反射体进行了成像和关联，但尚未可靠地追踪到大陆下方，尽管对现有广角反射数据的分析表明这些反射体确实在苏格兰大陆下方投射。本研究将探讨精细上地幔结构宽带成像的科学潜力，以及不列颠群岛下主要地幔反射体的构造意义。该项目将支持在苏格兰部署一个为期两年的25个站点宽带地震网络，以执行以下任务。1)将上地幔反射体的地震特征与被动震源和主动震源记录进行对比。2)确定苏格兰大陆下地幔反射体的区域范围。3)研究上地幔反射体与古生代岩石圈尺度构造的几何关系。4)估算这些反射体及其周围岩石圈地幔的物理性质，包括各向异性。5)验证上地幔构造以新生代为主的假说。这项工作将利用国家科学基金会的资金和英国国家能源研究中心对布里斯托尔大学的现有支持，进行RUSH实验的第一阶段。