Accumulation rates, isotopic and molecular data of terrestrial carbon in sediments of the Laptev Sea continental margin

Jannik Martens, Tommaso Tesi, Valeriy Rusakov, Igor Semiletov, Oleg Dudarev, Örjan Gustafsson

This dataset contains isotopic (¹³C and ¹⁴C) and molecular biomarker data (lignin phenols, n-alkanes, n-alkanoic acids) of organic carbon in surface sediments of the Laptev Sea continental margin. We also present a collection of ²¹⁰Pbxs measurements in 12 shallow sediment cores and present a new terrestrial organic carbon (terrOC) budget for the entire Laptev Sea continental margin.

The dataset has been used to quantify accumulation rates of terrestrial carbon for the Laptev Sea slope and rise, and compare terrOC fluxes in these systems with shelf-based terrOC accumulation rates. Besides quantifying terrOC using dual-isotope (¹³C and ¹⁴C) source apportionment, we utilize concentrations, degradation proxies and relative abundances or terrestrial biomarkers to trace off-shelf terrOC transport and its remineralization.

The data builds on sediment samples taken along four transects, including a Laptev Sea shelf transect, a slope transect, as well as two shelf-slope-rise transects during Arctic Ocean expeditions in 2014 (SWERUS-C3) and in 2020 (ISSS-2020).

Citation

Jannik Martens, Tommaso Tesi, Valeriy Rusakov, Igor Semiletov, Oleg Dudarev, Örjan Gustafsson (2024) Accumulation rates, isotopic and molecular data of terrestrial carbon in sediments of the Laptev Sea continental margin. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/martens-2024-offshelf-terroc-1

References

Martens, J., Tesi, T., Rusakov, V., Semiletov, I., Dudarev, O., and Gustafsson, Ö., Terrestrial organic carbon transport, degradation and accumulation along the shelf-basin continuum of the Laptev Sea, Arctic Ocean. Accepted for publication in Global Biogeochemical Cycles.

Data description

The dataset is provided in one .xlsx spreadsheet file containing six data tables from the study by Martens et al., both in the main article and the supplementary information, with content as detailed below:

• Table 1: Overview of the sampling locations and data used in this study.
• Table 2: Mass accumulation rates (MAR) of sediments and terrestrial organic carbon (terrOC) across three depositional regimes of the Laptev Sea continental margin.
• Table S1: Biomarker data.
• Table S2: Results of dual-isotope source apportionments of OC.
• Table S3: Estimated terrestrial organic carbon (terrOC) budget of the Laptev Sea.
• Table S4: Radiochronological data (²¹⁰Pb and ²²⁶Ra) for sediment core slices from Laptev Sea continental slope and rise. Also shown are the bulk density (BD), the porosity, and the dry bulk density (DBD) when available.

Comments

The data presented in this dataset are also included in the supplementary information of the Martens et al. (2024) paper, but not in the form of one single spreadsheet file as made available here. Please, cite the article by Martens et al. (2024) when using this dataset.