Quirks & Quarks

Giant Icebergs Make Ocean Absorb Carbon

Giant, ten-kilometer-scale icebergs trail blooms of carbon-absorbing photosynthetic plankton, and might slightly slow global warming

Nutrients from melting Antarctic icebergs stimulates plankton growth

Satellite photo of iceberg B-15, one of the largest ever seen at 295 km long (MODIS/Terra/NASA)
Giant icebergs from Antarctica, more than 10km in length, have been found to be producing a green trail, as phytoplankton bloom in their wake.

Professor Grant Bigg, a professor of Earth Systems Science at the University of Sheffield, studied satellite images of enormous icebergs shed from various places around Antarctica, and discovered that they produced long-lasting blooms, due to the mineral nutrients, chiefly iron, that they'd picked up as they ground over the Antarctic continent.

The phytoplankton blooms absorbed and sequestered a significant amount of carbon dioxide, which suggests that as climate warming causes Antarctica to shed more ice, increasing blooms may increase carbon uptake in the Antarctic Ocean, which could act as a slight brake on warming.

Related Links

Paper in Nature Geoscience
- University of Sheffield release
CBC News story
BBC News story
The Guardian story