Full description

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

This 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: 10.1029/2007GC001743

Publication Abstract

We 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 Institutions

R. Dietmar Müller - EarthByte Research Group, School of Geosciences, The University of Sydney, Australia. ORCID: 0000-0002-3334-5764

Maria Sdrolias (now Maria Seton) - EarthByte Research Group, School of Geosciences, The University of Sydney, Australia. ORCID: 0000-0001-8541-1367

Carmen Gaina - Center for Geodynamics, Geological Survey of Norway, Norway

Walter R. Roest - Département des Géosciences Marines, Ifremer, France

Overview of Resources Contained

Age, 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 Resources

Note: 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 EarthByte

For more information about using GPlates, including tutorials and a user manual please visit GPlates or EarthByte