Article

2007-01-04 Science & Technology

250 Million years ago the EARTH got VERY SICK - not the meteor's fault.

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Posted by 3dc 2007-01-04 00:00|| || Front Page|| [2 views since 2007-05-07] Top

#1 George Bush was around back then?

Posted by Jackal">Jackal 2007-01-04 00:29|| http://home.earthlink.net/~sleepyjackal/index.html]">[http://home.earthlink.net/~sleepyjackal/index.html] 2007-01-04 00:29|| Front Page Top

#2 Correction #1 - STATE GOVERNATOR BUSH.

Posted by JosephMendiola 2007-01-04 00:58|| 2007-01-04 00:58|| Front Page Top

#3 This is certainly a plausible theory. But there are lots of plausible theories.

One that I keep seeing which makes a lot of sense is that mass extinctions can occur when an era's environment and its plants and animals have been around and relatively stable for so long that viruses and prions get the upper hand.

We've all heard about the "dinosaur killer" that hit the Earth in present day Mexico that supposedly wiped out the Cretaceous flora and fauna. A very sexy concept, no doubt. But what is less publicized is that the dinosaurs were on the ropes already by that time.

Careful analysis of fossils indicates that the number of species was already dwindling to near nothing. Something had decimated the dinosaurs before the impact, which really was nothing more than a final push off of a cliff.

Could widespread success of microbes have done this? Again, very plausible, and until now absolutely unprovable. Recently, though, paleontologists have found dinosaur soft tissue preserved in some fossils that may contain enough DNA for analysis.

It may be difficult if not impossible to prove, but if it is the case, it certainly has implications for our own era, at some point.

Posted by no mo uro 2007-01-04 07:01|| 2007-01-04 07:01|| Front Page Top

#4 I've always been partial to this explanation myself.

Posted by Mike 2007-01-04 10:02|| 2007-01-04 10:02|| Front Page Top

#5 I can accept a spectrum of theories causing both gradual and punctuated changes that result in die offs.

Other than those mentioned, there is the "toxic geology" theory, that underneath the ground there are several different things that might suddenly release vast amount of poisons into the atmosphere and water.

This includes massive underwater methane ice deposits that warm to a critical mass then blast vast amounts of methane gas all at once. Undersea volcanic calderas that acidify entire seas with sulfuric acid. Gigantic volcanic eruptions, etc.

Even good old petroleum may be more a product of geology than decay, and in past might have erupted in a giant sea of burning crude.

Meh. Stuff happens.

Posted by Anonymoose 2007-01-04 10:42|| 2007-01-04 10:42|| Front Page Top

#6 This does not seem very plausible to me considering the world is 6000 years old. And the Flood would hardly have any effect on these plankton things.

/your high-school curriculum

Posted by Excalibur 2007-01-04 10:49|| 2007-01-04 10:49|| Front Page Top

#7 Oh yeah, I forgot. We can just blame it on God, reduce it to some voodoo like cult belief and suppress any and all questions by saying you need to have faith. Move along now, nothing here to see.

Posted by bigjim-ky 2007-01-04 12:27|| 2007-01-04 12:27|| Front Page Top

#8 There is an article in the Oct '06 Scientific American that describes the process.

The thing is the process makes good biological sense and seems very plausible. I've even seen it first hand in aquariums (though not exact same trigger, but a disruption of the system in some way).

In a nutshell:

1) Period of high vulcanic activities raises atomospheric CO2 and Methane

2) A greenhouse process starts to raise ocean temps

3) Warmer water dissolves far less oxygen

4) This starts to raise the chemocline, the boundary between anoxic water and oxygenated water. Usually this is a stable layer, but the rising temps allow less oxygen so the boundary moves closer to the surface

5) Anaerobes start claming the new teritory that is now condusive to their growth. The Hydrogen sulfide levels begin to go up. This cycle is self-accelerating because die off because of the H2S only provides more nutrients for the anaerobes to grow faster and produce more H2S

6) Chemocline layer reaches close to surface of oceans and H2S begins to bleed heavily into atmosphere (whilst killing much in the oceans)

7) H2S in atmosphere begins decimating land based life.

8) As concentration of H2S rise in atomosphere, it begins to attack ozone

9) UV starts to take toll / combined with the H2S it is a nasty one-two punch

Now, from owning several large (180g - 700+ g) saltwater aquarims, I can say for certain that a warm tank and H2S are a major danger, as it will decimate a tank with only a little release. And I mean decimate.

Disturbing Anoxic regions of your sand (and releasing H2S) will decimate everything. What does survive, if anything, won't last long.

Nutrient levels start to increase geometric and the algeas at surface start to go nuts (but only for a little bit), starving off even more oxygen.

What's worse, you tend to get bacterial blooms with even further consumption of oxygen. This allows the boundary to rise all the way to surface. Algaes will die off as soon as the H2S starts to reach them. The aerobic bacteria are gone, the algae are gone, the anerobes eat what remains from die off. Once they've consumed what's there, most die off, until you are left with only a few anaerobes and a barren waste land.

I've seen this run-away in a few hours killing everything from a small release (note, in aquriums, the algae usually don't have time to do much, because the depth of most tanks allows the H2S to spread up water colmun very quickly).

However in oceans, the algaes would take off for a while on the surface allowing even less to dissolve in the water (surface agitation allows the oxygen to dissolve, a bloom of algae prevents completely). The bacteria begin doing their thing, and well, it is all over in a very short time, be it oceans or a tank.

The key in this (from Earth's view) is throwing the balance of Chemocline off, so that it moves closer and closer to the surface. Once past threshold, it is all over.

That's the key to theroy, everything is great until temps rise causing far less oxygen to dissolve and 'artificially' allowing the boundary to move past threshold, triggering a cascade that is so fast most things cannot react (nor could they as to most H2S is killer) - essentially it removes the gas exchange from the system and suffocates.

Also, emperically, you have a choice with your closed water systems. Run them warmer for increased metabolism and activity (say growth in fish and corals) or run them cooler with less metabolism but more oxygen. Most of us running salt water tanks involving coral will run 2 - 4 degrees cooler than their natural environment.

This is because although very stable for the most part, once something goes out of whack in a minor way, running it cooler can give you time to adjust and react before a cascade.

Now, I am not saying this happened in the past, but the theory makes good sense from my Biochem side and Emperical evidence from running salt water systems.

Posted by bombay">bombay 2007-01-04 18:18|| 2007-01-04 18:18|| Front Page Top

15:15 wxjames
23:46 Ricky bin Ricardo (Abu Babaloo)
23:32 Ricky bin Ricardo (Abu Babaloo)
23:30 Ricky bin Ricardo (Abu Babaloo)
23:23 SteveS
23:22 Verlaine
23:20 ed
23:16 Mike N.
23:13 USN, ret.
23:11 USN, ret.
23:11 SteveS
23:06 ed
23:02 mrp
23:01 JosephMendiola
23:01 USN, ret.
23:00 Frank G
22:54 USN, ret.
22:52 Killer Rabbit
22:49 Frank G
22:49 USN, ret.
22:47 Frank G
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22:45 ed
22:45 Frank G