Mass extinction: our collision course

[chequita guevara]

Originally posted by CorpusScorpius
Wasn't there some natural disaster in the middle ages that dimmed the sun light on earth for a year or so?

Krakatoa erupts so violently every 150 years as to destroy its island. In 535, the eruption caused Justian's plague (and thus the slow collapse of the Eastern Roman Empire), set the Avars on their Westward trek, caused the collapse of a couple American Indian civizations, brought about the end of Roman Britain (which had still been fighting off the Saxons), and quite a few other things as well. It is likely reponsible for the little ice age at the begining of the 14th Century and caused the year without a summer in the 19th.

Krakatoa is just a regular, though very active, volcano.

[Dinner]

I understood the late PErmian event to be caused by the "Snow Ball Earth" event during which glaciation occured within 10-15 degrees north or south of the equator. Let me pull out my old "Geologic Catastrophes" text book and see if I'm remembering correctly or not.

[MrFun]

I'm still worried about our bannana supply . . . . .

[The Mad Monk]

Snowball or fireball -- make up your minds!

[Dinner]

Originally posted by chegitz guevara
Krakatoa is just a regular, though very active, volcano.

Yeah you’re right. The really mega volcanoes no longer exist. For the 2.5 billion years of the Earth's history the Earth's mantle was still hot enough (both from residual accreationary heat and from greater radioactivity) to produce crystallite pipes. Crystallite pipes were volcanoes which were so large and erupted so violently at pressures so great that diamonds and other crystals were formed as the magma shot up the volcano's throat.

There's a diamond mine in northern Canada where the diamonds were created in this fashion.

[Dinner]

Originally posted by The Mad Monk
Snowball or fireball -- make up your minds!

The Permian was so long ago that much of the geologic formations don't exist any more (we're talking WAAAAAAAAYYY before the dinosaurs; around 250 million compared to 65 million years ago) so it is hard to say 100% what happened. There are lots of competing theories about what happened but one thing is certain 90% of all marine life ceased to exist at the end of the Paleozoic.

Still it's an important period because all of the known living animal phyla appeared within a few millions of years and roughly halfway in to the Permian animals, fungi, and plants all colonized the land and the insects became the first flying life on Earth.

[Dinner]

Re: Re: Mass extinction: our collision course

Originally posted by DAVOUT
Was it not 65 millions years ago that the dinosaurs made room available for us ?

Yes. There were several mass extinctions through out the Earth's history history but the end Permian event was the worst.

[mrmitchell]

I've said it once and I've said it again.

It's better that the Earth is destroyed by a vague, guilt-creating catastrophe than by a country whose name starts with U and ends with nited States of America.

[Odin]

This is what caused the Permian extictions:

1. An asteroid hits the area that is now the shallow sea between Argentina and the Falkland Islands.

2. The shockwaves concentrate at the exact opposite point of the earth, Siberia, causing enourmous volcanic activity

3. Some extinctions in the oceans

4. Average global temperature increases by 5 degrees C, realeasing methane from the ocean floors.

5. Massive land extintions

6. The average global temperature increases by 5 MORE degees.

7. Massive ocean extinctions

8. 95% of species extinct, Triassic Period begins

The great Permian extinction massacred the Paleozoic inveretabrates, including the coral-making cnidarians of the time, coral reefs would not return untill modern stoney corals evolve in the Jurassic. Most of the Mammal-like reptiles die out and are replaced by the Archosaurs, the group that crocs and dinos (including birds) belong to, as the dominant large land animals.

[Dinner]

You can't really say 95% of all species went extinct because 9/10 plus of our date is all near shore marine animals because that's where the best conditions for preserving fossiles exists. Of course any anoxic enviroment will work and the faster the specimen is buryed the better but the way fossils are traped does create a satistical bias.

[Dinner]

From the BBC http://www.bbc.co.uk/education/darwi...es/permian.htm
[/quote]
estimated that as many as 96% of all marine species were lost, while on land more than 3 quarters of all vertebrate families became extinct[/quote]

Do you see the difference in extinction rates between land and sea creatures? Remember it is much, much more difficult to create a fossile on land then at sea. Now that we realize our fossil record is biased towards near shore marine species then you can figure out the next contributing factor.

Suppose you are a near shore animal like a clam and you want to find yourself a happy little home. The more shore line there is then the more potential habitate area you have but the less shore area there is in the world the less habitate you have. It just so happens that Pangea (the best known of the super contents) was formed at the end of the Permian so instead of 6-8 contents, each with shore lines, we now have one big content and all of the near shore animals must be crowded into a smaller area. Add on to this that if you are a clam in a closing sea way it isn't like you can justhike over land a couple of hundred miles to get to the new ocean and even if you do make it to the new shore areas then you still have to worry if it's the right temperature for you. Tropical animals don't do well in sub artic places and the creation of the super content ment things were getting colder fast because of changing ocean currents.

[Agathon]

Don't you know that this is just God's angry rumblings because the world is rapidly becoming a 21st century Sodom. I mean, those perverted child-molesting gays are getting married and pornography is on display in public places, clearly visible to children (despite the best efforts of J. Ashcroft Esq.); the television is awash with filthy degenerates and good honest white people can't find work because of affirmative action.

His judgement cometh and that right soon.....

[mrmitchell]

Agathon, don't do that. I have to deal with people that actually believe that every day

[Agathon]

Originally posted by mrmitchell
Agathon, don't do that. I have to deal with people that actually believe that every day

You better repent, boy!!!!!!

Anyway, the above is soon coming to a church near you.

[Dinner]

A brief over view of the four leading theories for the Permian extinction.

http://hannover.park.org/Canada/Museum/extinction/permcause.html