Comet caused the great global warming some 56 million years ago – lagranepoca

Comet caused the great global warming some 56 million years ago.

Researchers presented evidence that supports the hypothesis that it was the impact of a comet which preceded the global warming some 56 million years ago, during the period of thermal Maximum of the Paleocene-Eocene.

This remarkable event marked the end of the Paleocene, and gave start of the Eocene. The Isthmus of Panama at that time did not exist, and the sea moved freely between the Pacific Ocean and the Atlantic. The planet has already suffered from a gradual global warming so that it had almost no important layers of ice.

"The coincidence of an impact with a big climate change is more than remarkable", pointed to the October 13, the authors led by Morgan Schaller, a professor of environmental science at the Rensselaer Polytechnic Institute in New York.

The analysis of the sediments of this period revealed the presence of microtectitas, a few tiny areas of vitreous normally dark, is already known, are formed by impacts of extraterrestrial: comets, asteroids, and various meteorites.

Tectita. Mineral dry product of an impact of a Meteorite, Comet or Asteroid. Photo of file. (Wikimedia Commons)

Mr. Schaller explained that he was actually looking in the sediments of that era, fossils of foraminifera, a small organism with shell, but what I found were the microtectitas.

Foraminifer. Shell of Heterostegina depressa. (Wikimedia Commons)

"we Were having bad luck in search of foraminifera, and I was frustrated. I went to the lab, and threw a sample in the tray classification without sifting, and there were," said Schaller. "it Was an awesome moment. I knew that what I was seeing was not normal".

Microtectitas in a sediment sample. (Rensselaer Polytechnic Institute)

"had Not been detected before," he said in the study. The research posits that had not been seen because of the color of these crystals, which are dark, not distinguishable when compared among a tray of selection of color black, which they used to sift the clear foramínidos.

The change to a tray, white, we began to see quite a few microtectitas, with a maximum of 3 per gram.

"Some microtectitas of the samples contained even 'quartz deformed’," the report adds. This made them think in a definite evidence that its source was produced by an impact. The samples exhibit microcráteres or all were sintered together.

"This is evidence of the speed at which they traveled as they are solidified and hit the floor."

some 56 million years Ago, during the event’s thermal Maximum of the Paleocene-Eocene, "the atmospheric carbon dioxide increased rapidly, accompanied by a peak in global temperature of about 5 to 8 degrees Celsius, lasted for about 150,000 years ago", noted the authors.

The graph shows the evolution of the climate during the last sixty-five million years ago. The thermal maximum of the Paleocene-Eocene (MTPE) is highlighted in red. (Wikimedia Commons)

Stressed that "although much is known of this fact, had not determined the source of the carbon dioxide, and little is known about the exact sequence of events."

that happened was that the carbon dioxide entered the atmosphere quickly, and the rate the temperature began to rise, they added.

about showed a sudden change of the isotopes of carbon, in particular in the foramínidos. The carbon isotopes are atoms with neutrons unequal to the number of protons that reveal characteristics of the atmosphere. They were stable but is suddenly changed in the atmosphere. Her recovery took 150,000 years ago.

The study proposes that the comet contributed to the changes, "but it was too small to explain the whole of the event. Most likely he acted as a trigger for the release of carbon additional from other sources".

Comet del1680 on Rome. (Wikimedia Commons)

The results were published in the journal Science. Participated in addition the professor Rensselaer Miriam Katz and graduate student Megan Fung, of Rensselaer; James Wright, of Rutgers University, and Dennis Kent of Columbia University.

The remains of a comet is scattered and your evidence today is in the sediments.

"This tells us that there was a impact alien at the time that this sediment was deposited – a space rock hit the planet," said Morgan Schaller.

sediment samples were conducted at different sites, including the surface, to rule out that have been contaminated during the drilling process.

Other events were key to the global warming prior to the Earth. Some suggest that what actually led to the extinction of the dinosaurs, 10 million years ago that the age of the sediments analyzed in the study, that is to say makes 66 million years ago, was also a comet, instead of a large asteroid, when in the Yucatan, there was a great impact of the same.