Final Report Summary - EARTHSEQUENCING (A new approach to sequence Earth history at high resolution over the past 66 million years)
The project is organised into four components:
Objective A: Develop the first complete cyclostratigraphic age model for the Eocene based on a single locale from IODP Exp. 342 and thus use these successions as a Rosetta Stone to close the ‘Eocene tuning gap’. Tie data into an absolute anchored chronological age model using consistent, reproducible and self-documented workflows; integrate these new age scales to provide a full Earth Sequence for the past 66 million years. This objective has now been fully achieved: High-resolution X-ray fluorescence Core data have been obtained from IODP Expedition 342 as part of a consortium effort. These data, primarily from Site U1408 and U1410 have been used to close an important time scale gap in the middle Eocene, and are currently expanded and verified by new data from IODP Site U1514 (Mantelle Basin). These new records allow the connection of previously astronomically calibrated data sets for younger and older ages, and now results in a fully connected astronomically calibrated geological time scale throughout the Cenozoic. In addition, work has been completed to arrive at the first part (latest Eocene to present) of a Cenozoic “megasplice”. Closely related data collection and interpretation of stable isotope data have been published.
Objective B: Extract and constrain orbital components from geological data to verify, constrain and improve astronomical calculations. The aim is to reverse the traditional approach of comparing and time-adjusting geological data to pre-calculated astronomical models by first arriving at an anchored time scale based on the stable 405 kyr cycle, and then extracting unknown (tidal dissipation) or poorly constrained (obliquity) variations at and beyond the limit of validity of astronomical calculations (~50–55 Myr ago). Work on this objective is ongoing, and current progress consists of verifying a new methodology by the PI with more recent astronomical solutions, and to collect new relevant data during a field campaign in Argentina extending the approach to the Mesozoic in order to gain a larger signal-to-noise ratio of the imprint of tidal dissipation. As a corollary to this project, new progress has been made in determining the optimum data resolution in order to extract astronomical parameters from geological data.
Objective C: Examine the magnitude (and sensitivity) of orbitally paced climate and carbon cycle dynamics across the Paleogene and test hypotheses relating to the global nature of major Eocene carbon cycle events, and Earth System Sensitivity. This sub-project started in mid-2016. Initial progress consists of setting up a relevant Earth System Model of Intermediate Complexity (cGENIE, cooperation with Andy Ridgwell and Sandy Kirtland-Turner, U Riverside), and to explore sensitivity experiments with static and dynamic orbital forcings over long multi-Myr time periods. The models results are currently being prepared for publication. In addition, collaboration on background theory development and strategies resulted in a publication by von der Heydt et al., 2016.
Objective D: Develop a new IT based “Earth sequencing” workflow that can integrate, visualise and process all relevant geological data and astronomical time series. This sub-project is the most challenging in terms of new database and numerical algorithm and software development. Major progress has been achieved on the following points: A new database system has been set up, utilising a “NoSQL” system with additional unique software compression techniques. The main outcome of this approach is that existing IODP high-resolution data sets that are used by sub-projects A-C are now organised in a comprehensive standard way, and importantly, are accessible and discoverable by algorithmic means. In particular, data access times compared to the IODP data warehouse have been increased by a factor of around 10-30, making the ambition of developing “Earth sequencing” workflows feasible. Currently about 50 GB of data have been organised, and is available via https://paloz.marum.de also for external scientists via a simplified data portal. Software development on the scientific workflow management, based on the system “Kepler” is in good progress, with initial integration of data injection from the described database system, as well as the development of new software “actors” that can ingest and process the datasets.