http://www.abc.net.au/news/2017-06-15/climate-change-antarctic-volcanoes-shed-new-light/8619574

 

A team of scientists has found evidence that ancient volcanoes in Antarctica played a role in global climate and could help combat climate change now.

 

A study, published in the journal, Nature Communications, explains how the chance discovery of a calcite crust in Antarctica, confirmed the region was subject to volcanic activity 24,000 years ago.

The calcite was found by New Zealand-based geomorphologist, Paul Augustinus, who became stranded in Antarctica's Boggs Valley during a snowstorm.

While waiting for his helicopter to arrive, he began looking around and spotted some unusual deposits.

He sent them to the University of Newcastle's Silvia Frisia, a crystal expert who led the study.

Antarctic volcanoes create subglacial lake

Associate Professor Frisia examined the calcite using an electron microscope and realised it contained fluorine and sulphur, which are signs of volcanism.

She said the eruption would have melted the ice and formed a large subglacial lake.

The iron-rich subglacial waters eventually reached the southern ocean, creating a large algal bloom, which in turn sequestered massive quantities of carbon dioxide from the atmosphere.

Associate Professor Frisia said it was an important discovery, as scientists explore the idea of replicating the process to halt climate change.

"People are trying to replicate that and this is why the study of the subglacial environment is becoming so hot a topic," she said.

"People are trying to fertilise the southern ocean artificially.

"The problem is that you need to find exactly the right iron that fertilises the ocean, the right form of iron, so maybe we are providing these people with some useful information.

"I should say this is an ingredient, one more ingredient in the complexity of what regulates the climate at a global scale, because we don't know what might happen once Antarctica starts melting.

"In the Antarctic peninsula we already know there is delivery of iron off the Antarctic peninsula which is causing fertilisation.

"Greenland is also delivering iron, but the northern ocean is a different story.

Southern Ocean 'a powerful influence' on climate

Fellow researcher at the University of Newcastle Dr Andrea Borsato said the Southern Ocean had a powerful influence over the Earth's climate, storing much of the Earth's carbon.

"The Southern Ocean is a dominant player in the Earth's carbon cycle," he said.

"A critical component is 'iron fertilisation' that causes massive algal blooms and the subsequent transfer of organic carbon from the surface to the depths.

"Until now this fertilisation was attributed to dust, however, we have discovered another way this can happen - though Antarctic volcanism.

"The ability of the southern ocean to continue to sequester large volumes of carbon dioxide and slow the rate of climate change is unknown, which is why this new discovery is valuable.

"It has solved another missing piece of the puzzle," Dr Borsato said.

Associate Professor Frisia said she was hopeful the information would prove useful in advancing knowledge of climate change processes.

"What gives me hope is that Earth might have its own way of regulating itself.

"I'm not sure that we will survive as a species, but I know that life will survive, and that's what gives me hope.

"What excites me as a living being is that life goes on, because bacteria will always go on, and will always combine and manufacture something different and that's why I'm positive."