Scientists have placed tighter constraints on the amount of material expelled into the atmosphere by the Chicxulub impact:
Scientists say they now have a much clearer picture of the climate catastrophe that followed the asteroid impact on Earth 66 million years ago. The event is blamed for the demise of three-quarters of plant and animal species, including the dinosaurs. The researchers' investigations suggest the impact threw more than 300 billion tonnes of sulphur into the atmosphere. This would have dropped temperatures globally below freezing for several years. Ocean temperatures could have been affected for centuries. The abrupt change explains why so many species struggled to survive. "We always thought there was this global winter but with these new, tighter constraints, we can be much more sure about what happened," Prof Joanna Morgan, from Imperial College London, told BBC News.
Quantifying the Release of Climate-Active Gases by Large Meteorite Impacts With a Case Study of Chicxulub (open, 9DOI: 10.1002/2017GL074879) (DX)
Potentially hazardous asteroids and comets have hit Earth throughout its history, with catastrophic consequences in the case of the Chicxulub impact 66 Myr ago. Here we reexamine one of the mechanisms that allow an impact to have a global effect—the release of climate-active gases from terrestrial sedimentary rocks after the high-velocity impact. We estimate that 325 ± 130 Gt of sulfur and 425 ± 160 Gt CO2 were ejected into the atmosphere at velocities > 1 km/s. These numbers have to be used in global climate models to quantify possible changes of solar irradiation, surface temperature, and duration of stressful conditions for biota.
Also at the American Geophysical Union.
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The Chicxulub impact event is credited with causing the extinction of all non-avian dinosaurs around 66 million years ago. Now, a study in Nature suggests that dinosaurs could have survived if the asteroid had landed in an ocean or almost any bit of land that wasn't loaded with hydrocarbons:
[...] the extraterrestrial impact happened nearly anywhere else, like in the ocean or in the middle of most continents, some scientists now say it is possible dinosaurs could have survived annihilation. Only 13 percent of the Earth's surface harbored the ingredients necessary to turn the cosmic collision into this specific mass extinction event, according to a study published Thursday in the journal Scientific Reports [open, DOI: 10.1038/s41598-017-14199-x] [DX]. "I think dinosaurs could still be alive today," if the asteroid had landed elsewhere, Kunio Kaiho, a paleontologist from Tohoku University in Japan and lead author on the study, said in an email.
Other researchers questioned their findings.
When the asteroid, which had a diameter about half the length of Manhattan, struck the coast of Mexico, it found a rich source of sulfur and hydrocarbons, or organic deposits like fossil fuels, according to the researchers. Scorching hot temperatures at the impact crater would have ignited the fuel. The combustion would have spewed soot and sulfur into the stratosphere in sufficient quantities to blot out the sun and change the climate, setting into motion the collapse of entire ecosystems and the extinction of three-quarters of all species on Earth.
[...] Eighty-seven percent of Earth's surface, places like most of present day India, China, the Amazon and Africa, would not have had high enough concentrations of hydrocarbons to seal the dinosaurs' fate. But if the asteroid had hit marine coastal areas thriving with algae, which would have included present day Siberia, the Middle East and the eastern coast of North America, the bang would have been about as devastating to the dinosaurs and life on Earth as the Chicxulub impact.
Humans should burn off all of the hydrocarbons and tar sands in the Earth's crust, so we can make our species more resistant to impactors.
Also at DW, The Atlantic, and Live Science.
Related: Asteroid Impact That Killed Off the Dinosaurs Quantified
(Score: 0) by Anonymous Coward on Friday November 03 2017, @01:47AM (4 children)
Might as call them "magicians says".
Y'all go ragging on "mainstream media" science reporting, but how is SN any better?
(Score: 5, Touché) by takyon on Friday November 03 2017, @02:01AM
We link to the peer-reviewed paper.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 0) by Anonymous Coward on Friday November 03 2017, @02:25AM (1 child)
Scientists are like magicians. They gave you the magical modern world you live in.
Without them you'd still be riding a horse to your farm fields & cutting your wheat with your scythe, using candles for light, heating your one room home with wood, coal, or animal dung, surviving on canned preserves for five months of the year, never ever listening to recorded music let alone TV or movies, and enjoying the pleasure of having your broken leg set with no anesthesia. That, and 1000 other things we take for granted each day.
(Score: 0) by Anonymous Coward on Friday November 03 2017, @02:36AM
And you, unlike takyon, is an idiot.
(Score: 2) by Fluffeh on Friday November 03 2017, @03:45AM
Well, there's that old doozey courtesy of Arthur C Clarke - "Any sufficiently advanced technology is indistinguishable from magic" - but in this case, I guess you can substitute technology for science.
I guess with limited education or understanding, some of what scholars are discovering may come across as magic.
(Score: 0) by Anonymous Coward on Friday November 03 2017, @02:17AM (3 children)
It prevented the earth from getting even colder.
(Score: 0) by Anonymous Coward on Friday November 03 2017, @06:27AM
(Score: 0) by Anonymous Coward on Friday November 03 2017, @01:54PM
(Score: 2) by frojack on Friday November 03 2017, @09:23PM
And all that refined sulfur laying around, just waiting to get hit?
I note this is the same 66 million year ago event that was first diagnosed by the presence of larger than normal quantities of Iridium at a specific geologic layer. https://en.wikipedia.org/wiki/Iridium_anomaly [wikipedia.org]
This became commonly referred to as the KT boundary, and went on to become one of the key events in the mystery of where the dinosaurs went.
However, there's a significant amount of data suggesting these animals were well on their way out before the meteor hit.
http://www.sciencemag.org/news/2011/07/case-closed-dino-killer [sciencemag.org]
It seems the fossil finds of bones were petering out well below (and therefore before) the iridium rich KT boundary layer.
All the articles on this that I've read over the years on this, and none of them mention sulfur.
No, you are mistaken. I've always had this sig.
(Score: 2) by MostCynical on Friday November 03 2017, @08:24AM
it was the same size as the fish caught by the one-armed man:
(Hold out one arm) "This big"
"I guess once you start doubting, there's no end to it." -Batou, Ghost in the Shell: Stand Alone Complex