This data product comprises 5 files, containing marine sediment pore water and solid phase leachate silicon (Si) isotopic and element concentration data, as well as benthic silica flux magnitudes derived from core incubation experiments and sediment biogenic silica contents. Samples were collected over three cruises of the Changing Arctic Ocean Seafloor (ChAOS) project summer sampling campaigns in the Barents Sea between 2017 and 2019 aboard the RRS James Clark Ross (cruises JR16006, JR17007 and JR18006). The aim of this study was to improve our mechanistic understanding of the cycling of Si within the Arctic Ocean seafloor through measurement of stable Si isotopes in the dissolved Si pool and the solid phase sources. This project was part of the Changing Arctic Ocean programme, funded by the Natural Environment Research Council (NERC) (grant no. NE/P005942/1).

Samples of surface seawater were collected around giant icebergs A-76A (on cruise DY158) and A-23A (on cruise SD033) via the underway uncontaminated seawater systems on the RRS Discovery and RRS Sir David Attenborough respectively. Samples were collected with the motivation of identifying the biogeochemical impact of giant iceberg passage on the surrounding surface ocean. Data was collected via sensors of the uncontaminated seawater system for temperature, salinity, and chlorophyll-a concentration. Samples were taken for lab analysis upon return to the UK for dissolved macronutrients (nitrate, nitrite, phosphate, silicic acid), oxygen isotopes, and dissolved silicon isotopes. Funding has been provided by National Environment Research Council via: - C-CLEAR Doctoral Training Partnership (NE/S007164/1) - BIOPOLE (NE/W004933) - SiCLING (NE/X014819)