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extinctions possibly explained

varek

varek

Commander
Red Shirt
A team of scientists at the Chinese Academy of Sciences, led by Yong Wei, have speculated that the Earth’s atmosphere may have lost millions of tons of oxygen during the Triassic-Jurassic magnetic pole reversal, about 200 million years ago.

http://blogs.discovermagazine.com/d-brief/2014/06/10/earths-magnetic-flips-may-triggered-mass-extinctions/#.U5nH4bFQZV-

http://en.wikipedia.org/wiki/Triassic_Extinction

This could explain what made most land creatures go extinct then and could also explain what may have happened on Mars, if life existed there before such a cataclysmic event, that is.
 
Boy, oh boy...if only we could Really slingshot around the sun...for my money, however, the theory of the Giant Meteor makes the most sense...so far...
 
I don't think they've got the extinction trigger because they say that the oxygen levels only dropped by 4.5 percent from their modeled pole-reversal, for a total of 9 percent. I'm currently living in a city with 4.5 percent below-standard O2 partial pressure, and come from a town with about 9 percent less O2 partial pressure. Denver's oxygen levels are almost 18 percent below standard, and life there shows no signs of an eternal mass extinction.

Oxygen levels need to drop by about 40 percent before you really notice it, and by over 60 percent before adaptation takes more than a week or two.
 
gturner said:
Denver's oxygen levels are almost 18 percent below standard, and life there shows no signs of an eternal mass extinction.
Click to expand...

Maybe not mass extinction, but I definitely noticed the lack of oxygen when I drove out to Colorado last year. I was exhausted for two full days before my body finally adapted to it.
 
RoJoHen said:
gturner said:
Denver's oxygen levels are almost 18 percent below standard, and life there shows no signs of an eternal mass extinction.
Click to expand...

Maybe not mass extinction, but I definitely noticed the lack of oxygen when I drove out to Colorado last year. I was exhausted for two full days before my body finally adapted to it.
Click to expand...



...was there for a week in December, and will be again in August, and I could not help notice an increase in C2H5OH levels...including mine...also did notice a distinct shortness of breath, and also what looked like a TOTAL extintion of a certain age group...bodies everywhere...clothing torn...missing...it was a real sight to see...

:rofl:
 
I am sceptical about this theory. A reduction of oxigen by 9% would merely mean a drop from 21% to approximately 19%. That's hardly a lethal level, considering that we can easily survive in crowded classrooms or meeting rooms which contain about 17% oxigen. Levels under 15% influence your ability to think, levels around 10% make you faint, less than 8% oxigen means you suffocate.

Even if dinosaurs were a little more vulnerable to oxigen reduction, it's still not all that likely that they all died.

Also, the instant the air loses oxigen, the levels are replenished by free oxigen from the oceans (it's a dynamic balance). So that the marine animals should have been effected just as strongly as the terrestrial ones. Which afaik they weren't.
 
Okay...I promised to post "the answer" to the extinction of the dinosaurs...but I need to locate some material for my presentation. Bear with me...life's demands are putting a damper on revealing "the truth"!

So I guess you can treat this class as a study hall...so start making paper airplanes. :lol:
 
LMFAOschwarz said:
Okay...I promised to post "the answer" to the extinction of the dinosaurs...but I need to locate some material for my presentation. Bear with me...life's demands are putting a damper on revealing "the truth"!

So I guess you can treat this class as a study hall...so start making paper airplanes. :lol:
Click to expand...

Darn...just got my grades...flunked
Study Hall and Paper Airplane Making...
 
Rhubarbodendron said:
I am sceptical about this theory. A reduction of oxigen by 9% would merely mean a drop from 21% to approximately 19%. That's hardly a lethal level, considering that we can easily survive in crowded classrooms or meeting rooms which contain about 17% oxigen. Levels under 15% influence your ability to think, levels around 10% make you faint, less than 8% oxigen means you suffocate.

Even if dinosaurs were a little more vulnerable to oxigen reduction, it's still not all that likely that they all died.

Also, the instant the air loses oxigen, the levels are replenished by free oxigen from the oceans (it's a dynamic balance). So that the marine animals should have been effected just as strongly as the terrestrial ones. Which afaik they weren't.
Click to expand...
Remember that when speaking in the context of geologic time, that 9% reduction in oxygen would have occurred over the course of hundreds of thousands of years, and would have LASTED for half a million years, with the extinction event spread out over a similar timespan. That second point bears repeating: mass extinctions do not occur over a small number of lifetimes for the animals in question, and are only "sudden" in the context of geologic time.

The thing is, the reduction in oxygen means larger species will have, on average, slower metabolisms and reduced energy and vitality than their ancestors. Accordingly, they have shorter lifespans, produce less offspring and are slightly less aggressive throughout their lives. If they are out-competed for resources by smaller life forms better adapted to the lower oxygen levels, then this makes their lives even harder. A persistent drop in the birthrate of, say, 5%, coupled with a slight increase in the mortality rate would shrink the population of a particular species over time, and if the conditions that caused those new rates persists for half a million years, then they eventually die out.
 
usually, larger animals have a longer lifespan than small ones.
Apart from that detail I find no flaw in your argumants. Still, would living in somewhat stale air really decrease the birth rate? Reptilian fertility is usually just dependent on temperature and food quality.
 
Ironically, an earlier catastrophe allegedly occurred--sometimes called the "oxygen catastrophe"--in which cyanobacteria produced too much oxygen for the organisms living then!

http://en.wikipedia.org/wiki/Oxygen_catastrophe

You can't win them all, no matter which way you go!

The tetaoxygen molecule (O4) was discovered in 2001, and it was proven in 2006 to be created by increasing pressure on O2 to 20 GPa. Tetraoxygen is actually part of a rhombohedral cluster of oxygen, O8. This form of oxygen can be used for rocket fuel!

http://en.wikipedia.org/wiki/Oxygen
 
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A 9 percent decrease in O2 shouldn't have much of an effect on land organisms, since the majority of land organisms already live with lower oxygen levels than that (average continental height above sea-level is 3,000 feet) and the history of the continents isn't one giant mass extinction event.
 
varek said:
Ironically, an earlier catastrophe allegedly occurred--sometimes called the "oxygen catastrophe"--in which cyanobacteria produced too much oxygen for the organisms living then!

http://en.wikipedia.org/wiki/Oxygen_catastrophe

You can't win them all, no matter which way you go!

The tetaoxygen molecule (O4) was discovered in 2001, and it was proven in 2006 to be created by increasing pressure on O2 to 20 GPa. Tetraoxygen is actually part of a rhombohedral cluster of oxygen, O8. This form of oxygen can be used for rocket fuel!

http://en.wikipedia.org/wiki/Oxygen
Click to expand...

Perhaps palcohol as well
http://up-ship.com/blog/?p=24274

Now I have also heard a lot about Nitrogen 20 (N20)
I wonder if China Lake 20 (explosive) is the same thing.

Boron is also good. The best hypergolic fuel was pentaborane--but it was vile stuff.
http://en.wikipedia.org/wiki/Pentaborane
 
Hypoxia was an important contributor to the end-Permian extinction and, to a lesser extent, the end-Triassic extinction, although climate warming and (in the ocean) ocean acidification were more important. However, this new theory can't be correct because it doesn't agree with the tempo of extinction. Both extinctions were extremely rapid (the Permian extinction took only a few tens of thousands of years), not what you would expect from a cumulative reduction in oxygen levels from more frequent reversals. They don't invoke a single magnetic field reversal (which would obviously be crazy, as those occur all the time), but rather argue that certain times had more frequent reversals that would gradually allow oxygen to escape. The timescales of oxygen loss (gradual) and extinction (sudden) don't match, and I can't think of a plausible mechanism for threshold effects (like where a sudden extinction can be triggered at a particular threshold within decreasing oxygen).
 
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