RECALIBRATION OF THE SEDIMENT WEDGE MODEL (CONTINENTAL SHELF-SLOPE-RISE STRUCTURES) COMPONENT FOR THE OESBATHY V1.011

OESBathy is a systematic scientific procedure for paleobathymetry reconstruction, integrating 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 submerged heterogeneous continental margins called the sediment wedge model (SWM). This SWM, which is one of the unique fundamental components of the OESBathy, and this makes OESBathy standout from the other ocean reconstruction methods. The SWM, representative of continental shelf-slope-rise structure, is typically calibrated at modern active and passive continental margins of varying natures, completing the bathymetry reconstruction extending from the ocean crust to the coastlines.

In this project, this currently three-parameter SWM is restructured with improved model practices. The updates include enhanced understanding of the modern shelf-slope-rise characteristics and improvement in the statistical parametrization. Detailed systematic study of modern shelf-slope-rise regions are performed at a higher spatial resolution. Modern ocean bathymetry data was acquired from a bedrock version of ETOPO1 global relief data. The regions studied include the coastal regions of the North, South, and Central Atlantic, part of the Southern Ocean between Australia and Antarctica, and the eastern margin of Pacific Ocean off the west coast of South America. Though the prime motivation of the project is to explore the coastal regions where a complete history of seafloor spreading is preserved, some additional anomalous areas with extended/stretched margins, like regions around Falkland Island and the northern coast of Siberia, are also explored for the first time and are to be included in the model.

Accordingly, a larger number of records were obtained for the subsequent statistical analysis. Additional adjustments have been made in the previously used statistical techniques (OESBathy 1.0 SWM) to improve the parametrization of the modeled widths of the continental shelf, slope and rise in the updated SWM. This updated SWM is incorporated in the improved OESBathy v1.011, and used to reconstruct the ocean bathymetry during the Paleocene-Eocene Thermal Maximum (PETM) around 56 million years before today.