OESBATHY V1.011: AN UPDATED METHODOLOGY FOR RECONSTRUCTING GLOBAL OCEAN BATHYMETRY WITH GENERALIZED CONTINENTAL SHELF-SLOPE-RISE STRUCTURE

A paleo-ocean bathymetry reconstruction for Paleocene-Eocene Thermal Boundary (56 Ma), commonly known as PETM, is presented here in a 0.1° x 0.1° resolution for use in paleo-climate studies. The reconstruction methodology OESBathy (version 1.011) adopted here is an updated version of OESBathy v1.0. This three-step procedure for paleobathymetry reconstruction integrates an abyssal ocean from standard plate cooling model for the oceanic lithosphere based on the age of the oceanic crust, modeled global oceanic sediment thicknesses and a submerged heterogeneous continental margins typically known as sediment wedge model. The age of the ocean floor for the PETM is adopted from the Earthbyte Project and the boundary coastlines are derived from the PALEOMAP Project. To calculate the depth-to-basement using the standard plate cooling model, required parameter values are obtained from published data for the modern oceans. On top of the depth-to-basement, a modeled multilayer improved sediment layer was added, derived from area-corrected published global sediment thickness data. Lastly, a parameterized sediment wedge model is added to connect the coastline with the closest ocean crust. The parameters for the sediment wedge model are re-calibrated using empirical relationships obtained from detailed study of modern ocean coasts, both active and passive margins, where a complete history of seafloor spreading is preserved and some additional anomalous coastal areas with extended/stretched margins, like regions around Falkland Island and the northern coast of Siberia.

In OESBathy v1.011, two out of three principal components are updated. The depth-to-basement component remains as it is while the modeled multilayer sediment layer and the sediment wedge model is improved. This updated OESBathy v1.011 is expected to display improved sediment cover and better shelf-slope-rise structures in the reconstructed bathymetry. Here, the PETM reconstructed bathymetry is presented, as modeled with the OESBathy v1.011. Sea plateaus and seamounts are also added on top of the reconstructed bathymetry. Finally, a comparison of this reconstructed paleo-bathymetry is presented to the PETM bathymetry published at Earthbyte website for the PETM.