Ancient Volcanic Eruptions In Antarctica Sparked Rapid Climate Change At The End Of Ice Age
A series of ancient eruptions from a large volcano lying in West Antarctica could have set off a melting event and widespread climate change that helped warm the southern hemisphere at the end of the last ice age.
Abrupt Climate Change
The climate change that started about 17,700 years ago included an abrupt poleward shift in westerly winds that encircle Antarctica as well as changes in sea ice extent, ocean circulation, and deep ocean ventilation.
Findings of a new study, which was published in the journal PNAS suggest that the series of volcanic eruptions of the stratovolcano Mount Takahe over a period of 192 years could explain the climate change from the South Pole to the subtropics.
Detailed chemical measurements of Antarctic ice cores revealed that the ancient eruptions of Mt. Takahe occurred exactly with the onset of Southern Hemisphere's most rapid, widespread climate change at the end of the most recent ice age.
Ice cores taken from across Antarctica showed evidence of high levels of sulfur and rare earths emitted over 192 years and the highest concentrations suggests of Mount Takahe eruptions.
Finding The Link Between Volcanic Eruptions And Climate Change
The researchers said that the eruptions were rich in chlorine and fluorine based on evidence they found in the snow.
The ancient series of volcanic eruptions in Antarctica released a haze of fallout that contained elevated levels hydrofluoric acid and heavy metals that extended over a span of at least 2,800 kilometers possibly even reaching southern South America.
The gases would have impacted the stratosphere in a similar way chlorofluorocarbons, which contain carbon, chlorine, and fluorine, and which were banned by the Montreal Protocol, affect the ozone layer. The fluorine-containing compounds damaged the ozone layer resulting in more solar radiation reaching Earth.
"Halogen-rich eruptions created a stratospheric ozone hole over Antarctica that, analogous to the modern ozone hole, led to large-scale changes in atmospheric circulation and hydroclimate throughout the Southern Hemisphere," explained Joseph McConnell, from the Desert Research Institute (DRI).
The researchers said that while the temperatures already show signs of rising at the time, the event sped up the process of climate change.
"The main message of the paper is that the climate sometimes only needs a relatively small push to flip it from one state to another. We should remember this today," said Jørgen Peder Steffensen, from the Niels Bohr Institute, University of Copenhagen,