Environment Chance discovery reveals how volcanoes help Southern Ocean store carbon dioxide

Chance discovery reveals how volcanoes help Southern Ocean store carbon dioxide

It’s the chance find that has solved a 24,000-year-old riddle— a mineral in an Antarctic valley has revealed that the region’s icy volcanoes play a crucial role in regulating the global climate.

The study, prompted by a curious-looking ‘calcite crust’ (a substance resembling rock to the untrained eye), was led by University of Newcastle Associate Professor Silvia Frisia.

The researchers found that volcanic activity in the Antarctic delivered iron-rich waters from below the ice to the Southern Ocean.

The iron delivered by the subglacial water fertilised the ocean, resulting in a large algal bloom which helped capture large quantities of carbon dioxide from the atmosphere.

Associate Professor Frisia says the surprising find may never have happened if a fellow researcher hadn’t been caught in a snowstorm.

“Paul Augustinus was stranded in Boggs Valley and being a scientist was poking around as he awaited helicopter pickup. He came across some deposits that did not make sense at that location,” Associate Professor Frisia said.

Calcite, typically only forms beneath thousands of metres of ice. Associate Professor Augustinus immediately recognised the mineral’s value as a window on the history of the Antarctic ice sheet.

The research team was puzzled at finding calcites where there is no ice today. Using DNA evidence preserved within the calcite they were able to show that volcanic activity when the glacier was at its maximum formed a large lake under the ice.

“This lake eventually discharged, flowing beneath the ice and collecting water from other pockets of iron-rich subglacial water along the way,” Associate Professor Frisia explained.

Fellow researcher Dr Andrea Borsato said he hoped the study would help to advance knowledge and understanding of global climate change.

“Currently scientists are exploring the idea of imitating the process that fertilises the Southern Ocean with iron to replicate past natural sequestration events,” Dr Borsato said.

“We hope that by understanding the past we can better help present research to counteract the effects of climate warming and, hopefully, better plan for the future.”

Read more about the incredible discovery here. Story credit: University of Newcastle newsroom.

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