The Paleocene-Eocene Thermal Maximum (PETM) is a period about 55 million years ago where the climate warmed more than 5 degrees Celsius over a period of 20 thousand years as a result of a surge of 2,000 gigatons of carbon released into the atmosphere. The PETM is associated with an enormous deep-sea mass extinction and with diversification of life on sea and land. The cause of the PETM has been a mystery.
At the recent annual meeting of the Geological Society of America a group of researchers presented research suggesting a large comet impact stirred up the carbon that led to the PETM. The crux of their argument, which was just published in Science , is the discovery of dark, glassy spheres, known as microtektites, found in New Jersey core samples. Microtektites are created and dispersed during high-speed impacts. Additionally, just above the microtektite layer is a charcoal layer with signs of charred plants that would come from widespread wildfires ignited by the impact.
This discovery has been flying around the community for a while and has generated a lot of excitement. Ellen Thomas, a geologist at Wesleyan University believes they have found microtektites. and if they can date them to the start of the PETM, she will consider it real evidence of an impact. “If they have not dated them,” she says, “I think they may well be contamination.”
Others, like Gerald Dickens, an oceanographer at Rice University in Houston, are not at all convinced: “They have completely misinterpreted the data and missed the correct, and more cool, story.” He argues that the microtektites and charcoal were distributed throughout the sediment layer, but microbial activity at the top of the layer degraded the material making it disappear. Since the remaining material is only at the bottom of the sediment, this results in the appearance of a boundary that looks important, but really isn't.
The scientists are cautious about how a small impact might fit in that chain of climate events—not all extraterrestrial strikes are the same. The PETM strike may have been a world-changing event like the dinosaur killer just 10 million years earlier. Or, it could have been like the object that struck and excavated the Chesapeake Bay 35 million years ago: locally devastating, but globally survivable.
(Score: -1, Flamebait) by Anonymous Coward on Sunday October 16 2016, @03:24AM
ALL OF THEM
(Score: -1, Redundant) by Anonymous Coward on Sunday October 16 2016, @03:40AM
Grab em by the Pussy, then eviscerate them.
(Score: -1, Spam) by Anonymous Coward on Sunday October 16 2016, @04:02AM
Rip off their cocks and shove their own cocks up their asses.
(Score: 2) by WalksOnDirt on Sunday October 16 2016, @04:44AM
So, they think an impact may have occurred around the Paleocene Eocene Thermal Maximum. That's plausible, although the article rightly points out some reasons for caution. Now, how do we go from a minor impact to a massive release of carbon? I don't see the mechanism here.
(Score: 2, Informative) by khallow on Sunday October 16 2016, @06:13AM
My wild assed guess is the area of maximal ignorance which probably still has limestone in it. That would be the continental shelf off of the Mid-Atlantic states. Perhaps where the Hudson River empties into the Atlantic (assuming that the impact was near where they found the tektites).
(Score: 0) by Anonymous Coward on Sunday October 16 2016, @04:48AM
I've got this one!
the climate warmed more than 5 degrees Celsius over a period of 20 thousand years as a result of a surge of 2,000 gigatons of carbon released into the atmosphere.
See, climate change is natural! Humans couldn't possibly release as much carbon as natural events!
The PETM is associated with an enormous deep-sea mass extinction
Hmm, that sounds bad.
(Not quoting the comma since it shouldn't be there. The part after the and can't be a complete sentence on its own. The PETM is associated with an enormous deep-sea mass extinction. The PETM is associated with diversification of life on sea and land. Hopefully Muphry's law doesn't strike me down.)
and diversification of life on sea and land.
There we are! See! Global warming is good!
(Score: 1) by khallow on Sunday October 16 2016, @05:36AM
(Score: 3, Insightful) by aristarchus on Sunday October 16 2016, @10:49PM
What do you mean, "sound"? And why are you calling it "truth"? Tarbaby, bro! Tarbaby!
(Score: 2) by martyb on Sunday October 16 2016, @12:08PM
I've updated the story; thanks for pointing this out! (BTW, Muphry notices "i've got this one" and smiles. =)
Wit is intellect, dancing.
(Score: 1) by khallow on Sunday October 16 2016, @01:43PM
The PETM is associated with an enormous deep-sea mass extinction and with diversification of life on sea and land.
Notice that you have two "ands" in it. The comma in question is appropriate because it tells you that the second "and" groups "sea" and "land" rather than "an enormous deep-sea mass extinction", "with diversification of life on sea", and "land". The comma should be there. Sorry. "A and B and C" is different from "A, and B and C".
The part after the and can't be a complete sentence on its own.
First, I've heard of this supposed rule. Given that I routinely make sentences of very incomplete sentence fragments (such as I did above), I'm really not feeling it.
(Score: 2) by hubie on Sunday October 16 2016, @08:55PM
Thanks for the comma support. I had it in there because I was joining two opposing ideas: a) the deep-sea extinction, and b) the sudden diversification of life in the sea and on land. Without the comma it sounds confusing that there was an extinction event in the sea, but that there was a diversification of life in the sea. I suppose I could have broken it up into two sentences, but as it was just background info setting up the story, I didn't want to put too much text at the expense of telling everyone what the real point of the story was.
That being said, I'm only just a simple country physicist and I have not had my writings subject to the rigorous criticism as my friends in the humanities have endured.
(Score: -1, Offtopic) by Anonymous Coward on Sunday October 16 2016, @06:40AM
Vote for a renewal of life forms of earth!
(Score: 0) by Anonymous Coward on Sunday October 16 2016, @05:11PM
Im not sure coolness is an appropriate metric here. Is that where we are headed? Scientific theories are to be judged on how cool they sound?
(Score: 0) by Anonymous Coward on Sunday October 16 2016, @08:57PM
He says first the story is correct, but also points out that it is also more cool. You can have the first without the second, but it is just that they go together in this case (in his opinion).