A Comprehensive Database for the Most Commonly Measured Paleoceanographic Proxies: Evaluating Global Carbon Burial Variations over the Last Deglaciation

Abstract:

The paleoceanographic community has measured physical and chemical properties of thousands of sediment cores, in order to reconstruct past oceanic conditions across a wide range of timescales. Most of these datasets were archived in online data repositories in order to facilitate later analysis. However, the diversity of proxy types and heterogeneous reporting standards have hindered the analysis of globally distributed paleoceanographic time series, despite the tremendous potential utility of large datasets. In order for the existing archives of paleoceanographic data to contribute towards important unanswered issues, the datasets must be readily accessible in an organized structure, with an appropriate unified age model for each sediment site.

Here we present a comprehensive database, built using MATLAB structure, for the most commonly measured proxies in marine sediment cores and surface sediment. These include the concentrations of carbonate, organic matter and opal, density of the sediment, the oxygen and carbon isotopic composition of benthic and planktonic foraminifera, sea surface temperature estimates, as well as chronological constrains. The records were downloaded from PANGAEA and NOAA databases and multiple records from the same sediment core were regrouped, allowing age models to be shared between records. The resulting database consists of more than 30,000 sites, facilitating rapid and accurate mapping of sediment composition for selected time periods, and retrieving and plotting time series.

The greatest hurdle identified in building a unifi­ed dataproduct of this type is inconsistency in the reporting of depth measurements and chronological information.

In our view, standardized reporting practices would greatly assist in developing global quantitative analysis, and requires community-wide action. We propose the development of a unified global sediment core registry, including metadata and chronological information for all marine sediment cores.

From this global database, we calculated changes in sedimentary mass accumulation rates for carbonate and organic carbon over the last deglaciation using hundreds of sediment cores. By comparing these with modern maps of carbonates and organic carbon burial, we evaluated the variations of carbon across the last deglaciation.