Age, spreading rates, and spreading asymmetry of the world's ocean crust

Age, spreading rates, and spreading asymmetry of the world's ocean crustThis data collection is associated with the publication: Müller, R. D., Sdrolias, M., Gaina, C., & Roest, W. R. (2008). Age, spreading rates, and spreading asymmetry of the world's ocean crust. Geochemistry, Geophysics, Geosystems, 9(4). doi: 10.1029/2007GC001743Publication AbstractWe present four companion digital models of the age, age uncertainty, spreading rates and spreading asymmetries of the world's ocean basins as geographic and Mercator grids with 2 minute resolution. The grids include data from all the major ocean basins as well as detailed reconstructions of back-arc basins. The age, spreading rate and asymmetry at each grid node is determined by linear interpolation between adjacent seafloor isochrons in the direction of spreading. Ages for ocean floor between the oldest identified magnetic anomalies and continental crust are interpolated by geological estimates of the ages of passive continental margin segments. The age uncertainties for grid cells coinciding with marine magnetic anomaly identifications, observed or rotated to their conjugate ridge flanks, are based on the difference between gridded age and observed age. The uncertainties are also a function of the distance of a given grid cell to the nearest age observation, and the proximity to fracture zones or other age discontinuities. Asymmetries in crustal accretion appear to be frequently related to asthenospheric flow from mantle plumes to spreading ridges, resulting in ridge jumps towards hotspots. We also use the new age grid to compute global residual basement depth grids from the difference between observed oceanic basement depth and predicted depth using two alternative age-depth relationships. The new set of grids helps to investigate prominent negative depth anomalies, which may be alternatively related to subducted slab material descending in the mantle or to asthenospheric flow. A combination of our digital grids and the associated relative and absolute plate motion model with seismic tomography and mantle convection model outputs represent a valuable set of tools to investigate geodynamic problems.Authors and InstitutionsR. Dietmar Müller - EarthByte Research Group, School of Geosciences, The University of Sydney, Australia. ORCID: 0000-0002-3334-5764Maria Sdrolias (now Maria Seton) - EarthByte Research Group, School of Geosciences, The University of Sydney, Australia. ORCID: 0000-0001-8541-1367Carmen Gaina - Center for Geodynamics, Geological Survey of Norway, NorwayWalter R. Roest - Département des Géosciences Marines, Ifremer, FranceOverview of Resources ContainedAge, spreading rate and spreading asymmetry data for the world's ocean crust at present-day are provided in 2 and 6 minute resolution. Additionally, residual oceanic basement depths have been computed using different published age-depth relationships and these data have 5 minute resolution.List of ResourcesNote: For details on the files included in this data collection, see “Description_of_Resources.txt”.Note: For information on file formats and what programs to use to interact with various file formats, see “File_Formats_and_Recommended_Programs.txt”.Seafloor ages (.txt, .nc, .tif, .kmz, total 260.2 MB)Seafloor age error (.txt, .nc, .tif, .kmz, total 261 MB)Seafloor spreading rates (.txt, .nc, .tif, .kmz, total 263.1 MB)Seafloor spreading asymmetry (.txt, .nc, .tif, .kmz, total 262.8 MB)Seafloor residual basement depth (.txt, .nc, .tif, .kmz, total 507.1 MB)Colour palette files (.cpt, total 29 KB)Maps (.jpg, total 20.7 MB)For more information on this data collection, and links to other datasets from the EarthByte Research Group please visit EarthByteFor more information about using GPlates, including tutorials and a user manual please visit GPlates or EarthByte

全球洋壳的年龄、扩张速率及扩张不对称性

本数据收集关联于以下出版物：Müller, R. D., Sdrolias, M., Gaina, C., & Roest, W. R. (2008). Age, spreading rates, and spreading asymmetry of the world's ocean crust. Geochemistry, Geophysics, Geosystems, 9(4). doi: 10.1029/2007GC001743

出版物摘要
我们提出了全球洋盆年龄、年龄不确定性、扩张速率及扩张不对称性的四个配套数字模型（digital models），以2分分辨率的地理网格和墨卡托网格呈现。这些网格涵盖所有主要洋盆的数据，以及弧后盆地的详细重建结果。每个网格节点的年龄、扩张速率和不对称性通过扩张方向上相邻海底等时线（seafloor isochrons）之间的线性插值确定。最古老已识别磁异常与大陆地壳之间的洋壳年龄，通过被动大陆边缘（passive continental margin）段的地质年龄估计进行插值。与已识别海洋磁异常（marine magnetic anomaly）（观测到的或旋转至其共轭洋脊侧翼（conjugate ridge flanks）的）重合的网格单元的年龄不确定性，基于网格化年龄与观测年龄的差异。不确定性同时也是给定网格单元到最近年龄观测点的距离、以及与断裂带（fracture zones）或其他年龄不连续面的邻近度（proximity）的函数。地壳增生（crustal accretion）的不对称性似乎常与从地幔柱（mantle plumes）到扩张洋脊的软流圈流动（asthenospheric flow）相关，导致洋脊向热点跃迁（ridge jumps）。我们还利用新的年龄网格，通过观测洋壳基底深度与两种可选年龄-深度关系（age-depth relationships）预测深度的差异，计算了全球残余基底深度网格（residual basement depth grids）。这套新网格有助于研究显著的负深度异常（negative depth anomalies），其成因可能与地幔中俯冲板片物质（subducted slab material）的下沉或软流圈流动有关。我们的数字网格及相关的相对与绝对板块运动模型（relative and absolute plate motion model），与地震层析成像（seismic tomography）和地幔对流模型（mantle convection model）输出相结合，构成了研究地球动力学问题（geodynamic problems）的宝贵工具集。

作者及机构
R. 迪特马尔·穆勒（R. Dietmar Müller）- 澳大利亚悉尼大学地球科学学院EarthByte研究组，ORCID：0000-0002-3334-5764
Maria Sdrolias（现名Maria Seton）- 澳大利亚悉尼大学地球科学学院EarthByte研究组，ORCID：0000-0001-8541-1367
Carmen Gaina - 挪威地质调查局地球动力学中心
Walter R. Roest - 法国Ifremer海洋地球科学系

资源概述
提供了现今全球洋壳的年龄、扩张速率及扩张不对称性数据，分辨率为2分和6分。此外，利用已发表的不同年龄-深度关系计算得到了残余洋壳基底深度数据，其分辨率为5分。

资源列表
注：关于本数据收集中包含的文件详情，请参见“Description_of_Resources.txt”。
注：关于文件格式及用于交互各类文件格式的程序信息，请参见“File_Formats_and_Recommended_Programs.txt”。
海底年龄（.txt、.nc、.tif、.kmz，总大小260.2 MB）
海底年龄误差（.txt、.nc、.tif、.kmz，总大小261 MB）
海底扩张速率（.txt、.nc、.tif、.kmz，总大小263.1 MB）
海底扩张不对称性（.txt、.nc、.tif、.kmz，总大小262.8 MB）
海底残余基底深度（.txt、.nc、.tif、.kmz，总大小507.1 MB）
调色板文件（.cpt，总大小29 KB）
地图（.jpg，总大小20.7 MB）

关于本数据收集的更多信息，以及EarthByte研究组其他数据集的链接，请访问EarthByte。
关于GPlates的使用信息（包括教程和用户手册），请访问GPlates或EarthByte