DOI: 10.5285/148d0f6e-b4ec-45cc-af76-e0dad9e9faa5
title: Carbon Properties of Sediment Cores from the Southern Ocean and Wider Polar Front

description: This dataset presents a harmonised collection of sediment carbon measurements from over 2,000 cores collected across the Southern Ocean and Southern Hemisphere (wider polar front), south of 49 degrees. The dataset was compiled to enable quantitative assessments of sedimentary carbon stocks and identify regional hotspots and cold spots of blue carbon, as well as pinpointing trends and gaps in data collection. Drawing on published literature, data repositories, cruise archives, and correspondence with researchers, the compilation addresses longstanding fragmentation and inconsistency in sediment carbon reporting. The database includes measurements of total organic and inorganic carbon (TOC, TIC/CaCO3), and where possible some contextual biological information such as porosity, grain density and grain size. Additionally, where possible, data is georeferenced and cited (inclusive of access links) and further complimentary metadata is provided. The dataset may provide a key resource for future conservation planning, carbon accounting, and potentially climate modelling in polar marine ecosystems.
This project was funded by the World Wildlife Fund (WWF) grant number GB096001.
description: Data were systematically compiled from legacy databases, published articles, institutional repositories, and cruise reports. Each record was assigned a unique Core ID (as provided by authors) and standardised metadata including geographic coordinates, water depth, collection date, collection method and citation. Manual data entry was largely required due to inconsistencies in carbon reporting and significant errors uncovered during compilation.
Carbon measurements were collated in 1cm intervals up to 1m below the seafloor. Lookup tables were used for sediment classification based on particle size thresholds following a current best practise adapted Folk classification system.
description: Due to the manual requirements of the compilation, data assembly was conducted through Microsoft Excel (version 2408). Geographic presentation of data was conducted using ArcGIS Pro 3.2.1.
description: In some instances data has been averaged to account for intervals presented in this study (e.g., 0 - 0.5cm and 0.5 - 1cm have been averaged to produce a 0 - 1cm value). This may cause under or overestimations of carbon values in some instances, but is a necessary step to simplify the usage and presentation of the data. 

Where possible the database has been combed for null or obsolete values (e.g., negative or overly inflated carbon values, geolocations outside of scope), however due to the scale of data reported it is highly possible that errors will occur. 

As this is a compilation of other works (secondary data), assurances for data accuracy cannot be given. Any discrepancies or concerns with data presented here should be directed to the authors or data holders. 

When potential inaccuracies were uncovered during collation, authors were contacted for clarification. Vagueness (e.g., comments such as "most, but not all, of the cores in this study analyse the top 2cm of sediment") and seemingly incorrect values were continually present when identifying data for this dataset, therefore it is imperative to contact the cited authors if any additional clarification is required. 

Unknown metadata values are either listed as NaN or specified as unknown. Where appropriate data values less than or equal to 0.0 have been listed as "NaN" as they are believed to be either incorrect (negative values) or redundant (0 values).