Posted on 05/11/2016 12:34:28 AM PDT by blueplum
Full title: Ancient bubbles in Australian rocks show early Earth's air weighed less than half today's atmosphere
Air bubbles trapped in 2.7 billion-year-old Australian rock suggest the Earth's atmosphere weighed less than half of today and was much thinner than previously thought.
Researchers analysed the size of air bubbles that formed at the top and bottom of lava flows along the Beasley River in Western Australia's Pilbara region almost three billion years ago and used the data to calculate the atmospheric pressure at the time. The results suggest that the air at the time exerted at most half the pressure of today's atmosphere.
The findings, published on Monday in Nature Geoscience, reverse the commonly accepted idea that the early Earth had a thicker atmosphere to compensate for sunlight being about one fifth weaker than now. {snip} The result also reinforces Prof Buick’s 2015 finding that microbes were pulling nitrogen out of Earth’s atmosphere some three billion years ago.
“The levels of nitrogen gas have varied through Earth’s history, at least in Earth’s early history, in ways that people just haven’t even thought of before,” said co-author David Catling, a University of Washington professor of Earth and space sciences. “People will need to rewrite the textbooks.”
(Excerpt) Read more at telegraph.co.uk ...
courtesy ping :)
Will we be drowned or crushed first?
Only Al Gore knows for sure.
Would be interesting to see how they compensated for the fact that the air trapped in the Lava was superhot and expanded as well as stripped of most of it’s hydrogen and oxygen.
So a species "evolved" with useless wings? Pfftttt...
The dirt people probably used recent lava as a control.
Ancient bubbles, in my rocks
Makes me happy, makes me feel fine.
This is billions of years ago and long before the dinosaurs.
Perhaps the atmosphere was denser than today during the times of the pterodactyl
“Would be interesting to see how they compensated for the fact that the air trapped in the Lava was superhot and expanded as well as stripped of most of it’s hydrogen and oxygen.”
There was virtually no Oxygen in the Earth’s atmosphere until about that time. The Hydrogen and Ammonia that dominated the composition of the Earth’s first atmosphere was largely lost during and in the aftermath of the collision that created the Moon/Luna and finalized the Earth’s size and composition. This resulted in the Earth’s second atmosphere that was upwards of 100 times thicker and more massive than today’s atmosphere and was composed of greater than about 95 to 98 percent Carbon dioxide. This was an atmosphere that would have crushed today’s macro organisms. The microorganisms in that period of time were anaerobic, meaning they would have been poisoned by the presence of Oxygen in the atmosphere and hydrosphere. It was not until about the time of these rocks 2.7 billion years ago that aerobic, meaning Oxygen loving, life forms developed as life removed Carbon dioxide from the Earth’s atmosphere, metabolized the carbon into organic compounds, and released Oxygen into the atmosphere and hydrosphere. This massive release of Oxygen interacted with the massive quantities of iron in the lithosphere and the hydrosphere to produce massive quantities of Iron oxide (rust). This huge amount of Iron oxide rust produced the planet wide red rock layers until there was no longer enough iron left to react to the available Oxygen, which then allowed the Oxygen levels to increase beyond the previous micro trace amounts to become a substantial percentage of the Earth’s third atmosphere then composed for the most part of Nitrogen and Oxygen. The Carbon dioxide that previously had been almost the entire composition of Earth’s atmosphere when it was upwards of 100 times greater mass than today was almost entirely removed from the atmosphere by life, leaving only trace amounts and an atmosphere less than about 1 percent its previous mass and atmospheric pressure.
Hydrogen as an appreciable percentage of the Earth’s atmosphere had long ago been lost from the atmosphere, and Oxygen as more than a trace amount of the atmosphere was just beginning to accumulate in the Earth’s atmosphere for the first time as the Great Rusting event reached its peak activity and Oxygen was finally able to remain free in the Earth’s atmosphere.
Global Rusting ... the next big thing.
That is an amazing number of changes. I guess that would suggest that there are probably very few planets existing anywhere that have an atmosphere similar to earth’s.
What with practically every artifact found being dug up, dust from outer space falling by the mega-tons every year, I’d say the Earth diameter was much smaller eons ago also.
PV=zNRT
“That is an amazing number of changes. I guess that would suggest that there are probably very few planets existing anywhere that have an atmosphere similar to earth’s.”
If aerobic life developed on only one planet per million stars, the Milky Way Galaxy in which we live would be home to hundreds of thousands of such planets with Oxygen loving aerobic life. Within the visible Universe among the other galaxies, there would be uncounted trillions of such planets.
I recall that the prevailing theory was that the Earth built an atmosphere over time. This finding tends to support that notion.
“What with practically every artifact found being dug up, dust from outer space falling by the mega-tons every year, I’d say the Earth diameter was much smaller eons ago also.”
No, not really. The Earth is losing nearly twice as much mass as it gains each year according to some estimates. One of the estimates claims a net loss of 50,000 tonnes per year after a 40,000 tonne gain in gas, dust, and meteoric material. At those rates it would take trillions of years to make an appreciable change in the Earth’s mass. The Sun will either vaporize much of the Earth’s upper surface or consume the entire Earth within only a few billion years as the Sun swells in size to become a giant red star with its photosphere located somewhere near to the Earth’s present orbit. The Sun will either lose enough mass for the Earth’s orbit to expand outwards into the Solar system near to the present orbit of Mars, allowing a partially vaporized and smaller Earth to survive, or the Sun will expand beyond the Earth’s orbit and the Earth will be vaporized into hot gases and incorporated into the Red Giant Sun.
Fried Planets
http://science.nasa.gov/science-news/science-at-nasa/2012/25oct_friedplanets/
Man’s fault
Origin of the Earth’s Atmosphere
http://www.ux1.eiu.edu/~cfjps/1400/atmos_origin.html
The Climate System
EESC 2100 Spring 2007
Lectures - Monday and Wednesday, 11:00 AM - 12:15 PM
Lab - Tuesday, 4:10 PM -7 PM
http://eesc.columbia.edu/courses/ees/climate/lectures/earth.html
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