MOSAIC (Modern Ocean Sediment Archive and Inventory of Carbon): A (radio)carbon-centric database for seafloor surficial sediments

Abstract. Mapping the biogeochemical characteristics of surficial ocean sediments is crucial for advancing our understanding of global element cycling, as well as for assessment of the potential footprint of environmental change. Despite their importance as long-term repositories for biogenic materials produced in the ocean and delivered from the continents, biogeochemical signatures in ocean sediments remain poorly delineated. Here, we introduce MOSAIC (Modern Ocean Sediment Archive and Inventory of Carbon; DOI: https://doi.org/10.5168/mosaic019.1, mosaic.ethz.ch, Van der Voort et al., 2019), a (radio)carbon-centric database that seeks to address this information void. The goal of this nascent database is to provide a platform for development of regional to global-scale perspectives on the source, abundance and composition of organic matter in marine surface sediments, and to explore links between spatial variability in these characteristics and biological and depositional processes. The database has a continental margin-centric focus given both the importance and complexity of continental margins as sites of organic matter burial. It places emphasis on radiocarbon as an underutilized yet powerful tracer and chronometer of carbon cycle processes, and with a view to complementing radiocarbon databases for other earth system compartments. The database infrastructure and interactive web-application are openly accessible and designed to facilitate further expansion of the database. Examples are presented to illustrate large-scale variabilities in bulk carbon properties that emerge from the present data compilation.