High-resolution global bathymetry grids for key Cretaceous and early Cenozoic climate stages

• Other Authors: IMAS Data Manager (publisher), Institute for Marine and Antarctic Studies (IMAS), University of Tasmania (UTAS) (hasAssociationWith), Sauermilch, Isabel (pointOfContact), Sauermilch, Isabel (hasPrincipalInvestigator)
• Format: Dataset
• Language: unknown
• Published: University of Tasmania, Australia
• Subjects: geoscientificInformation; EARTH SCIENCE | OCEANS | MARINE GEOPHYSICS; EARTH SCIENCE | OCEANS | BATHYMETRY/SEAFLOOR TOPOGRAPHY; EARTH SCIENCE | OCEANS | OCEAN CIRCULATION | OCEAN CURRENTS; EARTH SCIENCE | OCEANS | OCEAN CIRCULATION | EDDIES; EARTH SCIENCE | CLIMATE INDICATORS | PALEOCLIMATE INDICATORS | PLATE TECTONICS; Marine Geoscience; EARTH SCIENCES; GEOLOGY; Tectonics; Geodynamics; GEOPHYSICS; Southern Ocean
• Online Access: https://doi.org/10.25959/5eb222a378c9a; https://researchdata.edu.au/high-resolution-global-climate-stages/1728210

Maintenance and Update Frequency: quarterly Statement: The paleobathymetry in this study is reconstructed for 38 Ma, using the plate tectonic model of Matthews et al. (2016)(31) in a paleomagnetic reference frame(32,33). Bathymetry at latitudes >40 °S is reconstructed following Hochmuth et al. (2019)(19), using sediment backstripping(34) with the software BALPAL(35). The grid is extended to the north (northern boundary at 25 °S and 0 °S, see Section 2.1) using the paleobathymetry of Baatsen et al. (2016)(36). The transition between both grids is smoothed to avoid artificial ‘jumps’ in the bathymetry. The maximum depth is set to 5500m. We use an approach that reconstructs ‘backwards’ in geological time, where sediment packages deposited since 38 Ma are removed from the present-day bathymetry(37), the plates reconstructed to their paleopositions(31), and sea level(38) and dynamic topography(39) changes are accounted for. Compared to ‘forward’ modelling techniques(40), this approach allows the preservation of realistic bathymetric features of seafloor roughness and small-scale, detailed geometry, such as fracture zones and seamounts, which are similar to the present-day, within the resulting paleogrid. Recent studies have shown that these small-scale features with slopes steeper than 0.05° significantly affect subsurface eddy velocities and the vertical structure of ocean circulation patterns(21,41). For the backstripping method, sediment thickness information is derived from seismo-stratigraphic interpretations, using seismic reflection and drilling data in the Southern Ocean(e.g., 42-46). Identified key seismic reflectors are converted from two-way travel time into depth below seafloor utilizing sonobuoy data and seismic reflection stacking velocities. Post-38 Ma sediments are ‘backstripped’ whilst underlying sedimentary material is decompacted. Sediment decompaction is calculated using the relationship between porosity and burial depth(47) for sand/silt in shelf and ooze in abyssal regions of the Southern ...