Chicxulub asteroid impact released more gas that thought

alibhai/ October 31, 2017/ New Gadgets/ 0 comments

  • Chicxulub asteroid impact triggered sulfur and carbon dioxide release
  • Released 325 gigatons of sulfur and 425 gigatons of carbon dioxide
  • This is more than 10 times global human emissions of carbon dioxide in 2014
  • lends support to the hypothesis that the impact played a significant role in the extinction event that eradicated 75% of Earth’s plant and animal species

The Chicxulub asteroid impact that many believed wiped out the dinosaurs released far more climate-altering gas into the atmosphere than originally thought, researchers have revealed.

It reveals for the first time how much sulfur and carbon dioxide gas was ejected into Earth’s atmosphere from vaporized rocks immediately after the event – triggering a ‘superwinter’.

The Chicxulub impact occurred 66 million years ago when an asteroid approximately 12 kilometers (7 miles) wide slammed into Earth. 

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The study reveals for the first time how much sulfur and carbon dioxide gas was ejected into Earth's atmosphere from vaporized rocks immediately after the Chicxulub impact 66 million years ago when an asteroid approximately 12 kilometers (7 miles) wide slammed into Earth.

The study reveals for the first time how much sulfur and carbon dioxide gas was ejected into Earth’s atmosphere from vaporized rocks immediately after the Chicxulub impact 66 million years ago when an asteroid approximately 12 kilometers (7 miles) wide slammed into Earth.

THE CHICXULUB EVENT

The Chicxulub impact occurred 66 million years ago when an asteroid approximately 12 kilometers (7 miles) wide slammed into Earth. 

The collision took place near what is now the Yucatán peninsula in the Gulf of Mexico. 

The asteroid is often cited as a potential cause of the Cretaceous-Paleogene extinction event, a mass extinction that erased up to 75 percent of all plant and animal species, including the dinosaurs.

 

The study’s authors estimate more than three times as much sulfur may have entered the air compared to what previous models assumed, implying the ensuing period of cool weather may have been colder than previously thought.

It lends support to the hypothesis that the impact played a significant role in the Cretaceous-Paleogene extinction event that eradicated nearly three-quarters of Earth’s plant and animal species, according to Joanna Morgan, a geophysicist at Imperial College London in the United Kingdom and co-author of the new study published in Geophysical Research Letters, a journal of the American Geophysical Union.

‘Many climate models can’t currently capture all of the consequences of the Chicxulub impact due to uncertainty in how much gas was initially released,’ she said.

‘We wanted to revisit this significant event and refine our collision model to better capture its immediate effects on the atmosphere.’

The asteroid collision had global consequences because it threw massive amounts of dust, sulfur and carbon dioxide into the atmosphere. 

The dust and sulfur formed a cloud that reflected sunlight and dramatically reduced Earth’s temperature. 

Based on earlier estimates of the amount of sulfur and carbon dioxide released by the impact, a recent study published in Geophysical Research Letters showed Earth’s average surface air temperature may have dropped by as much as 26 degrees Celsius (47 degrees Fahrenheit) and that sub-freezing temperatures persisted for at least three years after the impact.

Researchers studied the resulting crater from the impact zone in Mexico, known as the Chicxulub crater

Researchers studied the resulting crater from the impact zone in Mexico, known as the Chicxulub crater

In the new research, the authors used a computer code that simulates the pressure of the shock waves created by the impact to estimate the amounts of gases released in different impact scenarios. 

They changed variables such as the angle of the impact and the composition of the vaporized rocks to reduce the uncertainty of their calculations.

The new results show the impact likely released approximately 325 gigatons of sulfur and 425 gigatons of carbon dioxide into the atmosphere, more than 10 times global human emissions of carbon dioxide in 2014. 

In contrast, the previous study in Geophysical Research Letters that modeled Earth’s climate after the collision had assumed 100 gigatons of sulfur and 1,400 gigatons of carbon dioxide were ejected as a result of the impact.

WHAT HAPPENED WHEN THE ASTEROID HIT EARTH? 

Within 10 hours of the impact, a massive tsunami waved ripped through the Gulf coast.

This caused earthquakes and landslides in areas as far as Argentina. 

The creatures living at the time were not just suffering from the waves – the heat was much worse.

While investigating ‘dooms day’ researchers found small particles of rock and other debris that was shot into the air when the asteroid crashed.

After the asteroid had hit, the researchers believe that the Earth would have behaved like a ‘slow-moving fluid’

Called spherules, these small particles covered the world with a one-tenth inch thick layer of soot.

Experts explain that losing the light from the sun caused a complete collapse in the aquatic system as the phytoplankton base of almost all aquatic food chains would have been eliminated.

It’s believed that the more than 180 million years of evolution that brought the world to the Cretaceous point was destroyed in less than the lifetime of a Tyrannosaurus rex, which is about 20 to 30 years. 

 

The older models of the impact didn’t have as much computing power and were forced to assume all the ejected gas entered the atmosphere, limiting their accuracy, Artemieva said.

The study authors also based their model on updated estimates of the impact’s angle. 

An older study assumed the asteroid hit the surface at an angle of 90 degrees, but newer research shows the asteroid hit at an angle of approximately 60 degrees.

Using this revised angle of impact led to a larger amount of sulfur being ejected into the atmosphere, Morgan said. 

Along with gaining a better understand of the Chicxulub impact, researchers can also use the new study’s methods to estimate the amount of gas released during other large impacts in Earth’s history. 

For example, the authors calculated the Ries crater located in Bavaria, Germany was formed by an impact that ejected 1.3 gigatons of carbon dioxide into the atmosphere. 

This amount of gas likely had little effect on Earth’s climate, but the idea could be applied to help understand the climactic effects of larger impacts.

 





Courtesy: Daily Mail Online

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