An Analysis of Upper Mantle Heterogeneity and Anisotropy in Western North America Using Recordings Broadband Permanent and Temporary (PASSCAL) Seismic Stations

这项研究包括利用对整个大陆宽带站记录的地表波和体波的两种互补分析，确定北美上地幔的地震非均质性和各向异性。数据将从全球地震台网（GSN）、美国国家地震台网（USNSN）和临时部署的高性能pascal地震仪中检索。两种新的分析技术将用于探索地震各向异性的性质及其与大陆构造行为和演化的关系。第一种技术涉及多站差分相位延迟分析，应用于基波和高模表面波，包括洛夫波和瑞利波，在不同方位角上穿过阵列传播。这些数据将被反演成一个方位各向异性的三维模型，其长度尺度大致为100公里到1000公里。第二种技术包括测量整个区域的s波分裂时差。深度灵敏度是通过使用各种体波和表面波相位来实现的。将这些技术应用于横波在北美的传播，将阐明导致上地幔地震各向异性的基本地球动力学过程。

9814565GahertyThis research involves the determination of seismic heterogeneity and anisotropy in the upper mantle beneath North America using two complementary analyses of surface and body waves recorded at broadband stations across the continent. Data will be retrieved from the Global Seismic Network (GSN), the U.S. National Seismic Network (USNSN), and numerous temporary deployments of the high-capability PASSCAL seismometers. Two new analysis techniques will be applied to explore the nature of seismic anisotropy and its relationship to the tectonic behavior and evolution of the continent. The first technique involves multi-station differential phase-delay analysis applied to fundamental and higher-mode surface waves, both Love and Rayleigh waves, propagating across the array at various azimuths. The data will be inverted for a three-dimensional model of azimuthal anisotropy, with length scales spanning roughly a few 100 km to a few 1000 km. The second technique involves measuring S-wave splitting time separations throughout the region. Depth sensitivity is achieved through the use of a variety of body- and surface-wave phases. Application of these techniques to shear wave propagation across North America will illuminate the basic geodynamic processes giving rise to seismic anisotropy in the upper mantle.