Silicate content and stable silicon isotopic composition in seawater sampled during James Clark Ross cruise JR15003 in 2015 ...

• Main Authors: Cassarino, Lucie, Hendry, Katharine R, Henley, Sian Frances, MacDonald, Ellen, Arndt, Sandra, de Freitas, Felipe Sales, Pike, Jennifer, Firing, Yvonne L
• Format: Dataset
• Language: English
• Published: PANGAEA 2020
• Subjects: Benthic flux; continental shelf; early diagenesis; Silicon cyle; Event label; Campaign; Station label; Latitude of event; Longitude of event; DATE/TIME; DEPTH, water; Silicate; δ30Si, silicic acid; δ30Si, silicic acid, standard deviation; Multiple investigations; JR15003; James Clark Ross; Antarctic; Antarctic Peninsula; Austral; Antarc*
• Online Access: https://dx.doi.org/10.1594/pangaea.920055; https://doi.pangaea.de/10.1594/PANGAEA.920055

The West Antarctic Peninsula (WAP) is a highly productive shelf region during austral summer, supporting a rich ecosystem that has a significant impact on carbon sequestration. This ecosystem is heterogeneous, and characterised by biological "hotspots" fuelled largely by diatom production. The specific mechanisms determining the location and extent of these hotspots are not fully understood. Sedimentary enrichment of silicic acid (DSi) relative to other nutrients along the WAP, suggest that nutrient transfer across the sediment-water interface could have an impact on algal community composition. Here we combine reaction-transport modelling with porewater profiles of DSi concentration and stable silicon isotopic composition, biogenic silica content (BSi) and diatom abundances from sediment cores collected along the WAP, to assess the DSi flux and the processes that release this key nutrient from the WAP sediment into the overlying waters. We estimate a DSi diffusive flux of 2.67- 10**10 ± 2.75- 10**9 mol/yr ...