Volcanic Eruption in Australia Triggered First Mass Extinction
A new study suggests that an ancient volcanic eruption in Australia, some 510 million years ago, kick-started the world's first mass extinction.
The study was conducted by Curtin University researchers. The team measured the age of eruptions of the Kalkarindji volcanic province using advanced radio carbon dating techniques. The ancient lava once covered an area of 2 million square kilometres in the Northern Territory and Western Australia, according to a news release.
Researchers found that the volcanic eruptions occurred at the same time as the first mass extinction - Early-Middle Cambrian extinction. The event, considered to be caused by abrupt climatic changes, wiped out nearly all multi-cellular life on Earth.
Researchers said that the exact mechanism that led to this event was unknown, until now.
"Not only were we able to demonstrate that the Kalkarindji volcanic province was emplaced at the exact same time as the Cambrian extinction, but were also able to measure a depletion of sulphur dioxide from the province's volcanic rocks - which indicates sulphur was released into the atmosphere during the eruptions," said Fred Jourdan from Curtin's Department of Applied Geology, in a news release.
According to researchers, "small volcanic eruption" such as Pinatubo that erupted in 1991 released so much sulphur dioxide into the atmosphere that it cooled the Earth's temperature by few tenths of a degree for few years. The ash from Pinatubo covered an area of 21 square miles. The Kalkarindji was several times larger than the Pinatubo and could have easily started the chain of events that led to the demise of most creatures on earth.
The team compared the volcanic eruptions at Kalkarindji volcanic province to the volcanic regions elsewhere. Their research found that the mass extinction was preceded by abrupt fluctuation in climate, caused by large levels of sulphur dioxide and greenhouse gases.
"We calculated a near perfect chronological correlation between large volcanic province eruptions, climate shifts and mass extinctions over the history of life during the last 550 million years, with only one chance over 20 billion that this correlation is just a coincidence," Dr Jourdan added.
Researchers said that by looking at the past, the long-term effects of human-induced climate change can be understood.
The study is published in the journal Geology.
What's interesting is that volcanoes that are considered to be the harbinger for death and destruction can also support life during ice ages. A recent study had shown that Antarctic volcanoes have acted as cradles for life on Earth.