Did the Chicxulub asteroid knock Earth's thermometer out of the ballpark?

When the Chicxulub asteroid smashed into Earth 65 million years ago, the event drove an abrupt and long-lasting era of global warming, with a rapid temperature increase of 5 Celsius (C) that endured for roughly 100,000 years, a new study reports. The monumental event is a rare case where Earth's systems were perturbed at a rate greater than what's occurring now from human activity.

It therefore provides valuable insights into what may happen from sudden, extreme environmental changes.

The aftereffects of the Chicxulub impact remain debated, with some scientists advocating that soot within the atmosphere blocked out the sun sufficiently to drive global cooling; others suggest that carbon released from the Earth's crust into the atmosphere upon the asteroid's impact, as well as carbon from wildfires, had a warming effect.

To better understand how the temperature changed during this time, Ken MacLeod and colleagues analyzed a robust collection of well-preserved, sand grain-sized remains of fish teeth, scales and bone from a site in Tunisia; these samples retain oxygen isotopic signatures that reveal the temperature at the time that the related animal was alive.

The authors were able to collect samples from sediments that span the time leading up to the Chicxulub impact, until long afterwards.

Based on their analysis, they propose that global temperatures increased by about 5 C and did not cool to previous values for roughly 100,000 years after the impact, a magnitude and duration of warming closely matching levels of carbon dioxide that some types of analyses have estimated were emitted during the same period.

MacLeod et al. do note some discrepancy between their results and concentrations of atmospheric carbon dioxide derived from other kinds of analyses, which predict a more modest increase.

Research paper

Related Links
American Association for the Advancement of Science
Asteroid and Comet Mission News, Science and Technology

Tweet

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only

SpaceDaily Contributor
$5 Billed Once

credit card or paypal

Russian scientists use lasers to destroy mini asteroids
Washington (UPI) Mar 14, 2018
To simulate a nuclear explosion on an asteroid careening towards Earth, a team of scientists in Russia built miniature asteroid models and blasted them with lasers. The results of their experiments - published in the Journal of Experimental and Theoretical Physics - could help scientists better understand the type of explosive force needed to knock an Earth-bound asteroid off its collision course. Asteroids buzz by Earth all the time, and most of them are relatively small. But some ast ... read more