Surface Wave Tomography of the Arctic

摘要OPP-9818498 RitzwollerLevshin大型天然震源地震学提供的关于北极固体地球构造或构造史的信息很少。首席调查员将提供一个大大改进的地壳和岩石圈地震模型，其水平分辨率约为400-500公里，位于北极海底和周围高纬度以下至少150公里处。具有这一分辨率的新的地震模型将：1)提供更大的比例尺背景，以放置来自其他来源的新的和正在出现的信息；2)填补全球和地方信息之间的空白；3)补充大比例尺重磁异常图；以及4)阐明有关北极结构和构造的一些问题。由于北半球高纬度地区的台站和地震分布，利用面波探测北极地壳和岩石圈的结构是最好的。现在是开展面波层析成像研究的绝佳时机，原因有四：1)北极固体地球遗迹是地球上描述和了解最少的地区之一；2)远北宽带数字地震台站的数量在过去几年里急剧增长，其中大部分数据现在很容易获取；3)有效利用这些数据制作新的和更高分辨率的北极面波频散图和模型的方法基本到位；4)这项研究建立在首席调查员以前和正在进行的关于欧亚大陆和世界其他地区的面波频散和地壳和上地幔结构的研究基础上。第一部分：数据采集、处理、聚类和统计分析；第二部分，宽带(20 S-150年代)各向同性瑞利波和乐夫波频散图(群和相速度)的制作；第三部分，瑞利波和乐夫波相位和群速度频散图中方位各向异性估计能力的确定；第四部分，地壳和上地幔剪切速度模型的建立和表征。所有弥散测量和地图(各向同性和各向异性)以及最终的剪切速度模型将在北极层析成像网站上提供。大规模的自然震源地震学提供的关于北极固体地球构造或构造史的信息很少。首席调查员将提供一个大大改进的地壳和岩石圈地震模型，其水平分辨率约为400-500公里，位于北极海底和周围高纬度以下至少150公里处。具有这一分辨率的新的地震模型将：1)提供更大的比例尺背景，以放置来自其他来源的新的干旱新出现的信息；2)填补全球和地方信息之间的空白；3)补充大规模重磁异常图；以及4)阐明与北极结构和构造有关的一些问题。由于北半球高纬度地区的台站和地震分布，利用面波探测北极地壳和岩石圈的结构是最好的。现在是开展面波层析成像研究的绝佳时机，原因有四：1)北极固体地球遗迹是地球上描述和了解最少的地区之一；2)远北宽带数字地震台站的数量在过去几年里急剧增长，其中大部分数据现在很容易获取；3)有效利用这些数据制作新的和更高分辨率的北极面波频散图和模型的方法基本到位；4)这项研究建立在首席调查员以前和正在进行的关于欧亚大陆和世界其他地区的面波频散和地壳和上地幔结构的研究基础上。第一部分：数据采集、处理、聚类和统计分析；第二部分，宽带(20 S-150年代)各向同性瑞利波和乐夫波频散图(群和相速度)的制作；第三部分，瑞利波和乐夫波相位和群速度频散图中方位各向异性估计能力的确定；第四部分，地壳和上地幔剪切速度模型的建立和表征。所有弥散测量和地图(各向同性和各向异性)和最终剪切速度模型将在北极层析成像网站上提供。

Abstract OPP-9818498RitzwollerLevshinLarge-scale natural-source seismology has provided very little information on the structural or tectonic history of the Arctic solid earth. The Principal Investigators will provide a significantly improved seismic model of crust and lithosphere to a minimum of 150 km below the Arctic seafloor and the surrounding high northern latitudes with a lateral resolution of about 400-500 km. A new seismic model with this resolution will: 1) provide a larger scale context to place new and emerging information from other sources; 2) fill the void between global and local information; 3) complement large-scale gravity and magnetic anomaly maps; and 4) illuminate a number of questions concerning the structure and tectonics of the Arctic. Because of the station and earthquake distribution at high northern latitudes, the structure of the Arctic crust and lithosphere is best explored with surface waves. This is an excellent time to undertake a surface wave tomographic study for four important reasons: 1) Arctic solid earth remains is one of the most poorly characterized and understood regions on Earth; 2) the number of far northern broadband digital seismic stations has grown dramatically over the past several years and most of these data are now readily accessible; 3) the methodology to use these data effectively to produce new and higher resolution surface wave dispersion maps and models of the Arctic is largely in place; and 4) the study builds on the Principal Investigators' previous and on-going of surface wave dispersion and crustal and uppermost mantle structures beneath Eurasia and other regions of the world.This project will be divided into four parts. Part 1. data acquisition, processing, clustering, and statistical analyses; Part 2. production of broadband (20 s - 150s) isotropic Rayleigh and Love wave dispersion maps (groups and phase velocity); Part 3. determination of our ability to estimate azimuthal anisotropy in Rayleigh and Love wave phase and group velocity dispersion maps; and Part 4. construction and characterization of a shear velocity model of the crust and uppermost mantle. All dispersion measurements and maps (isotropic and anisotropic) and the final shear velocity model will be available on an Arctic tomography web site. Large-scale natural-source seismology has provided very little information on the structural or tectonic history of the Arctic solid earth. The Principal Investigators will provide a significantly improved seismic model of crust and lithosphere to a minimum of 150 km below the Arctic seafloor and the surrounding high northern latitudes with a lateral resolution of about 400-500 km. A new seismic model with this resolution will: 1) provide a larger scale context to place new arid emerging information from other sources; 2) fill the void between global and local information; 3) complement large-scale gravity and magnetic anomaly maps; and 4) illuminate a number of questions concerning the structure and tectonics of the Arctic. Because of the station and earthquake distribution at high northern latitudes, the structure of the Arctic crust and lithosphere is best explored with surface waves. This is an excellent time to undertake a surface wave tomographic study for four important reasons: 1) Arctic solid earth remains is one of the most poorly characterized and understood regions on Earth; 2) the number of far northern broadband digital seismic stations has grown dramatically over the past several years and most of these data are now readily accessible; 3) the methodology to use these data effectively to produce new and higher resolution surface wave dispersion maps and models of the Arctic is largely in place; and 4) the study builds on the Principal Investigators' previous and on-going of surface wave dispersion and crustal and uppermost mantle structures beneath Eurasia and other regions of the world.This project will be divided into four parts. Part 1. data acquisition, processing, clustering, and statistical analyses; Part 2. production of broadband (20 s - 150s) isotropic Rayleigh and Love wave dispersion maps (groups and phase velocity); Part 3. determination of our ability to estimate azimuthal anisotropy in Rayleigh and Love wave phase and group velocity dispersion maps; and Part 4. construction and characterization of a shear velocity model of the crust and uppermost mantle. All dispersion measurements and maps (isotropic and anisotropic) and final shear velocity model will be available on an Arctic tomography web site.