The Times Australia
The Times World News

.
The Times Real Estate

.

How a volcanic bombardment in ancient Australia led to the world's greatest climate catastrophe

  • Written by Timothy Chapman, Postdoctoral Fellow in Geology, University of New England
How a volcanic bombardment in ancient Australia led to the world's greatest climate catastrophe

Some 252 million years ago the world was going through a tumultuous period of rapid global warming.

To understand what caused it, scientists have looked to one particular event in which a volcanic eruption in what is now Siberia spewed huge volumes of greenhouse gas into the atmosphere.

However, there is evidence the climate was already changing before this.

Sea surface temperatures had increased by more than 6–8℃ in the hundreds of thousands of years leading up to the Siberian outpouring. Temperatures increased again after it, so much so that 85–95% of all living species eventually went extinct.

The eruption in Siberia obviously made a mark on the planet, but experts remained puzzled about what caused the initial warming before it.

Our research reveals Australia’s own ancient volcanoes played a big role. Prior to the event in Siberia, catastrophic eruptions in northern New South Wales spewed volcanic ash across the east coast.

These eruptions were so large they initiated the world’s biggest ever climate catastrophe — the evidence for which is now hidden deep in Australia’s thick piles of sediment.

Ancient volcanoes

Our study, published today[1] in Nature, confirms eastern Australia was shaken by repeated “super eruptions” between 256 and 252 million years ago.

Super eruptions are different to the more passive Siberian event. These catastrophic explosions spewed massive amounts of ash and gasses high into the atmosphere.

Today we see evidence of this in light-coloured layers of volcanic ash in sedimentary rock. These layers are found across huge areas of NSW and Queensland, all the way from Sydney to near Townsville.

Ash layers in coal measures
Thick pile of coal with multiple light coloured ash layers that represent volcanic eruptions sourced from the New England region and now in the Sydney basin. Ian Metcalfe

Our study has identified the source of this ash in the New England region of NSW, where the eroded remnants of volcanoes are preserved.

Though erosion has removed much of the evidence, the now innocuous-looking rocks are our record of terrifying eruptions. The thickness and spread of the ash produced is consistent with some of the largest volcanic eruptions known.

Eroded volcanoe Eroded remnants of the volcanoes in the New England region of NSW. Tim Chapman

How big were the super eruptions?

At least 150,000 km³ of material erupted from the northern NSW volcanoes over four million years. This makes them similar to the supervolcanoes of Yellowstone in the United States and Taupo in New Zealand.

To put it into perspective, the 79AD eruption of Mt Vesuvius, which obliterated the Italian city of Pompeii, produced just 3–4km³ of rock and ash. And the deadly Mt St Helens eruption in 1980 was about 1km³.

The Australian eruptions would have repeatedly covered the entire east coast in ash — metres thick in some places. And a massive outpouring of greenhouse gases would have triggered global climate change.

Environmental devastation

Ancient sedimentary rocks provide us with a timeline of the environmental damage caused by the eruptions. Ironically, the evidence is preserved in coal measures.

Today’s coal deposits in eastern Australia show ancient forests used to cover much of this land. After the super eruptions, however, these forests were abruptly terminated in a series of bushfires over some 500,000 years, 252.5–253 million years ago.

Read more: How Australia's geology gave us an abundance of coal – and a wealth of greentech minerals to switch to[2]

Typically the plant matter accumulated in swamps and was then buried under sediments. The burial process provided heat and pressure which enabled the conversion of the plant matter into coal.

Without the forests, there was no plant matter to accumulate. The ecosystem collapsed and most animals became extinct.

The subsequent eruptions in Siberia only exaggerated the devastation started by Australia’s supervolcanoes.

And this collapse of ecosystems was not limited to Australia, either. The catastrophic event affected all of the ancient continents. It had a substantial influence on the evolution of life — which eventually led to the rise of the dinosaurs.

Australia’s super eruptions were a key marker of change in the ancient world. As we look to achieving a more habitable climate in the future, who knew the clues to environmental catastrophe lay buried beneath our feet?

Acknowledgement: we would like to thank our colleague Phil Blevin from the Geological Survey of New South Wales for his contribution to this work.

Read more https://theconversation.com/how-a-volcanic-bombardment-in-ancient-australia-led-to-the-worlds-greatest-climate-catastrophe-178037

The Times Features

Best Deals on Home Furniture Online

Key Highlights Discover the best deals on high-quality outdoor furniture online. Transform your outdoor space into a stylish and comfortable oasis. Explore a wide range of d...

Discover the Best Women's Jumpers for Every Season

Key Highlights Explore lightweight jumpers for spring and summer, ensuring breathability and ease. Wrap up warm with cozy wool jumpers for the chilly autumn and winter season...

Uncover the Elegance of Gorgeous Diamond Tennis Necklaces

Key Highlights Diamond tennis necklaces are a timeless piece of jewelry that exudes elegance and sophistication. They feature a continuous line of brilliant-cut diamonds, cre...

Dental Implants vs. Dentures: Which Is Better for You?

When it comes to replacing missing teeth, two of the most common options are dental implants and dentures. Both have their advantages and disadvantages, so choosing between them ...

What Neck Pain Really Means (And Why It’s More Than Just Poor Posture)

Neck pain is often brushed off as something temporary — a tight spot after a long day at the desk or a poor night’s sleep. But when the discomfort keeps returning, it could be a ...

The Work of Gosha Rubchinskiy: Fashion, Culture, and Youth

From Designer to Cultural Architect Gosha Rubchinskiy is not just a fashion designer—he's a cultural force. Born in Moscow in 1984, Rubchinskiy began his career in fashion in t...

Times Magazine

The Essential Guide to Transforming Office Spaces for Maximum Efficiency

Why Office Fitouts MatterA well-designed office can make all the difference in productivity, employee satisfaction, and client impressions. Businesses of all sizes are investing in updated office spaces to create environments that foster collaborat...

The A/B Testing Revolution: How AI Optimized Landing Pages Without Human Input

A/B testing was always integral to the web-based marketing world. Was there a button that converted better? Marketing could pit one against the other and see which option worked better. This was always through human observation, and over time, as d...

Using Countdown Timers in Email: Do They Really Increase Conversions?

In a world that's always on, where marketers are attempting to entice a subscriber and get them to convert on the same screen with one email, the power of urgency is sometimes the essential element needed. One of the most popular ways to create urg...

Types of Software Consultants

In today's technology-driven world, businesses often seek the expertise of software consultants to navigate complex software needs. There are several types of software consultants, including solution architects, project managers, and user experienc...

CWU Assistive Tech Hub is Changing Lives: Win a Free Rollator Walker This Easter!

🌟 Mobility. Independence. Community. All in One. This Easter, the CWU Assistive Tech Hub is pleased to support the Banyule community by giving away a rollator walker. The giveaway will take place during the Macleod Village Easter Egg Hunt & Ma...

"Eternal Nurture" by Cara Barilla: A Timeless Collection of Wisdom and Healing

Renowned Sydney-born author and educator Cara Barilla has released her latest book, Eternal Nurture, a profound collection of inspirational quotes designed to support mindfulness, emotional healing, and personal growth. With a deep commitment to ...

LayBy Shopping