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  (Source: windows2universe.org)
Study shows plankton became more diverse during a time when oxygen levels spiked in Earth's earliest breathable atmosphere

Researchers from Ohio State University have found that plankton play a large part in understanding the origin of Earth's first breathable atmosphere.

Matthew Saltzman, study leader and associate professor of earth sciences at Ohio State University, and a team of researchers, have discovered that plankton are the key to understanding the gap between the atmosphere and 500 million-year-old chemical isotopes found in rocks. 

The Ohio State University team previously conducted a study that showed that upward displacements in the Earth's crust 500 million years ago lead to a reverse greenhouse effect, which cooled the oceans producing large plankton blooms, and sent oxygen into the atmosphere. 

Now, Saltzman and his team have discovered how oxygen disappeared from Earth's atmosphere during the Cambrian Period and then reappeared at higher levels. The team was able to quantify exactly how much oxygen was released during this period, and linked the amount of sulfur in oceans at that time with atmospheric carbon dioxide and oxygen. They also looked at how oxygen allowed a large amount of new life to thrive after it returned. 

"We know that oxygen levels in the ocean dropped dramatically [a condition called anoxia] during the Cambrian, and that coincides with the time of a global extinction," said Saltzman. "We still don't know why the anoxia spread all over the world. We may never know. But there have been many other extinction events in Earth's history, and with the exception of those caused by meteor impacts, others likely share elements of this one - changes in the balance of oxygen and carbon dioxide in the atmosphere and oceans."

When searching for what may have allowed oxygen back into the atmosphere and oceans 500 million years ago, researchers found that plankton played a huge role. During that time period, life didn't exist on land and life in the oceans was not as diverse as it is today, which made plankton a very big deal as far as ancient lifeforms go. 

Then a geologic event called the Steptoean Positive Carbon Isotope Excursion (SPICE) occurred, burying large amounts of organic matter in ocean sediments. This pulled carbon dioxide from the atmosphere and in turn, released oxygen. As plankton encounter oxygen, they become more selective for the "light isotope of carbon in carbon dioxide" and absorb it. 

Saltzman and his team looked at isotopes in fossilized plankton found in rocks located in the central United States, China and the Australian outback. They discovered that "plankton revolution," which is when plankton became more diverse, occurred around the same time as the SPICE event. 

"The amount of oxygen rebounded, and so did the diversity of life," said Saltzman. "We were able to bring together independent lines of evidence that showed that if the total oxygen was around 5-10 percent before the SPICE, then it rose to just above modern levels for the first time after the SPICE."

Information that the plankton have provided could be used to possibly deter climate change by changing the chemistry of the ocean to remove carbon dioxide. 

"When it comes to ancient life, they don't sound as exciting as dinosaurs, but the plankton are critical to this story," said Saltzman. 



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RE: Sounds familiar ...
By yxalitis on 2/28/2011 11:01:43 PM , Rating: 2
OK, I'll type slowly for you...
"What happens if there was a series of massive fissures that leaked water from earth's interior to the surface? The amount of oxygen in the ocean remains the same, but the amount of water has gone up, meaning the concentration of oxygen in the oceans drops!"
1. The Earth's interior is molten rock
2. The biblical flood is supposed to have taken place a few thousand years ago, not a few 100,000 years ago.
3. Why would this additional water, wherever it came from, have a different level of oxygen?
Comets are small, much much much smaller then the Earth, any Ice would make no difference to the Earth's ocean levels at all, or produce any noticeable or tangible rain.
4. Oh my, why am I bothering, you are clearly in logic-denial, as are all believers in the true word of the Bible.
Have you read Leviticus?


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