The impact of volcanism on trace metal biogeochemistry in the Southern Ocean ...

• Main Author: Holmes, Thomas
• Format: Thesis
• Language: unknown
• Published: University Of Tasmania 2023
• Subjects: Southern Ocean; Sea ice
• Online Access: https://dx.doi.org/10.25959/23238092.v1; https://figshare.utas.edu.au/articles/thesis/The_impact_of_volcanism_on_trace_metal_biogeochemistry_in_the_Southern_Ocean/23238092/1

Iron (Fe) is now recognised as a limiting, or co-limiting, micronutrient for biological production in the ocean. Areas of the ocean that are high in the macronutrients nitrogen (N) and phosphorous (P) but low in chlorophyll producing organisms are known as HNLC regions and cover approximately one third of the world's oceans, the largest of which is the Southern Ocean (SO). When coupled with the inhibition of nitrogen fixation by microbes under low Fe conditions in low-latitude regions, this means that Fe regulates biological productivity in as much as half the world's oceans. As such, Fe plays a key role in biogeochemical cycling and the drawdown of carbon from the atmosphere. Sources of Fe to the SO include resuspension of coastal and shallow sediments, glacial and iceberg melt, seasonal sea ice retreat, island wakes, vertical diffusive flux, interaction between bathymetry and currents, dust deposition and hydrothermal inputs. Hydrothermal inputs, in particular, have gained increasing recognition in recent ...