Collaborative Research: Complex Upper Mantle Structure Beneath Northeastern US Investigated Through Shear Wave Tomography

合作研究：通过剪切波断层扫描研究美国东北部下方复杂的上地幔结构

• 批准号: 9706195
• 负责人: William Menke
• 金额: $ 6.4万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-15 至 1999-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9706195&HistoricalAwards=false
• 关键词: Collaborative; Research; Complex; Upper; Mantle

9706195 Menke This research is a collaboration between Columbia University and Yale University involving the investigation of different types of mantle heterogeneity in the stable cratonic environment of the northeastern U.S. The strong heterogeneity in this geologically old region is unexpected since lateral temperature gradients - the main cause of heterogeneity in areas of active tectonics - are probably very subdued. Travel-time anomalies correlate with shear-wave splitting variations, so at least some of the heterogeneity is probably due to lateral changes in the orientation of mantle fabrics. This research will test the hypothesis that "anisotropic domains," coherent volumes of strained mantle rock related to past tectonic activity, are the primary source of traveltime heterogeneity. The data are to come from seismograms recorded by the recent high density of fixed and portable stations in the northeastern U.S. to form a dataset of body wave traveltimes and shear wave splitting measurements. ***

小行星9706195 这项研究是哥伦比亚大学和耶鲁大学之间的合作，涉及在美国东北部的稳定地幔环境中不同类型的地幔异质性的调查。在这个地质古老的地区，强烈的异质性是出乎意料的，因为横向温度梯度-活动构造地区异质性的主要原因-可能非常温和。 走时异常与剪切波分裂变化相关，因此至少有一些不均匀性可能是由于地幔组构方向的横向变化。 本研究将检验“各向异性域”这一假说，即与过去构造活动有关的应变地幔岩石的相干体积是走时不均匀性的主要来源。 这些数据将来自美国东北部最近高密度的固定和便携式台站记录的地震图，以形成体波走时和剪切波分裂测量的数据集。 ***