Revealed how giant icebergs breathe life into remote oceans
Prof Grant Bigg Professor in Earth Systems Science, University of Sheffield
Extract: Why icebergs mean oceans store more carbon Here’s how it works: as Antarctic ice sheets slowly slide towards the ocean they bump along the continent’s bedrock, picking up iron and other nutrients which become imprisoned within the ice. When icebergs melt they release these chemicals into the sea. As icebergs are essentially freshwater, their water is buoyant and ascends to the ocean surface, where the iron and nutrients are utilised by phytoplankton – tiny plant-like organisms at the bottom of the marine food web. This makes a big difference in the Southern Ocean, where limited dissolved iron – important for cell growth – restricts productivity despite an abundance of nitrate. Melting icebergs release iron in a bio-available form, so encourage phytoplankton growth, photosynthesis, and the draw-down of atmospheric CO2.
Read full article at The Conversation:
Full paper available at Nature Geoscience, (2016):
Enhanced Southern Ocean marine productivity due to fertilization by giant icebergs
Luis P. A. M. Duprat, Grant R. Bigg & David J. Wilton