Seismic velocity model layers, Eastern North American Margin Community Seismic Experiment (ENAM CSE)

This data set presents the velocity model interfaces. The velocity models were constrained by traveltime tomography of active-source Ocean Bottom Seismometers data along three profiles from the Eastern North American Margin Community Seismic Experiment (ENAM CSE). P-wave velocity models for Line 1, Line 2, and Line 3 are included as well as a S-wave velocity model for Line 3. Collectively, these tomographic velocity images reveal subsurface properties and information on the ancient rifting event between eastern North America and west Africa during the breakup of Pangea and formation of the Central Atlantic ocean, but may also be relevant for other studies such as modern processes along the margin. These data files are in ASCII format and describe the coordinates of layers within the velocity models. Each model consists of four layers (top to bottom): siliciclastic sediments, carbonaceous sediments, crust, mantle. Layer coordinates are exported every 180 meters in the X direction. Columns are: Layer ID, X-coordinate (km), Z-coordinate (km). Layer ID: 1 = seafloor, 2 = top of carbonates, 3 = top of basement, 4 = Moho. This data set was generated as part of the projects called Seismic study of mantle deformation and melt extraction during continental breakup in the ENAM primary site; and, Final stages of breakup and early spreading history of the Eastern North America passive margin from multichannel seismic data. Funding was providing through NSF awards OCE15-51717 and OCE15-51807.

本数据集展示了速度模型界面。所涉速度模型基于东北美陆缘社区地震实验（Eastern North American Margin Community Seismic Experiment, ENAM CSE）三条测线的主动源海底地震仪（Ocean Bottom Seismometers）走时层析成像数据约束得到。数据集包含第1、2、3测线的纵波（P-wave）速度模型，以及第3测线的横波（S-wave）速度模型。综合而言，这些层析成像速度图像可揭示泛大陆（Pangea）裂解、中央大西洋形成时期，北美东部与西非之间古裂谷事件的地下属性与相关信息，同时也可为陆缘现代过程等其他相关研究提供参考。本数据集的数据文件采用ASCII格式，记录了速度模型内部各层的坐标信息。每个速度模型均包含四层（自上而下依次为）：硅质碎屑沉积物、碳质沉积物、地壳与地幔。X方向上每180米输出一层坐标。数据列依次为：层ID、X坐标（单位：千米）、Z坐标（单位：千米）。层ID对应规则如下：1代表海底界面，2代表碳酸盐岩顶界面，3代表基底顶界面，4代表莫霍界面（Moho）。本数据集是两项研究项目的成果：其一为"ENAM核心区大陆裂解期地幔变形与熔体萃取的地震学研究（Seismic study of mantle deformation and melt extraction during continental breakup in the ENAM primary site）"，其二为"基于多通道地震数据解析东北美被动陆缘的裂解终期与早期扩张历史（Final stages of breakup and early spreading history of the Eastern North America passive margin from multichannel seismic data）"；本研究受美国国家科学基金会（National Science Foundation, NSF）项目OCE15-51717与OCE15-51807资助。