Mass Extinction

[Earniel]

Originally posted by Lizra
And they say it's safe!

Everything is safe - within a certain concentration or dose. Everything is lethal too, even ordinary water, as long as the dosis is high enough.

Atrazine is effective but it messes with hormones, which is safe to neither humans ór frogs alike IMO. Plus, it's pretty persistant in water and soil.

It's been recently banned completely in Belgium as far as I know. France banned it too 2 years ago. It's under consideration for a European ban last time I heard.

Originally posted by Insideous Rex
did you hear about that asteroid that ALMOST hit us just last week? Came within 26,000 miles. And you may say oh so what thats a big distance but its NOT believe me. Thats a fraction of a hairs width on a solar system scale. And this puppy was a good sized one. 100 meters accross. No not 10 miles like the one that wiped out the dinosaurs but you take a 100 meter rock going 40,000 miles an hour and slam it into new york and see what damage you do. I think we should all collectively heave a sigh of relief over this one. And hope the next one doesnt come even closer.

Interesting how we only hear about it afterwards isn't it? It's better that way IMO, it would only cause panic otherwise. Big chunks of rock fly through the galaxy every day, sooner or later it's going to be 'bullseye'. Rather later than sooner, as far as I'm concerned.

[Jonathan]

Originally posted by Eärniel
Interesting how we only hear about it afterwards isn't it? It's better that way IMO, it would only cause panic otherwise. Big chunks of rock fly through the galaxy every day, sooner or later it's going to be 'bullseye'. Rather later than sooner, as far as I'm concerned.

There are no good ways to detect such rocks when they approach the earth, they are simply too small and too dark. You only notice them only after they start burning in the atmosphere and, hopefully, either burn up or bounce off.

A few year's ago there was a glowing meteor in the sky over Stockholm. It was just the size of a tennisball or football but was very bright, though I only saw it on tv (I still curse myself for not giving the sky more attention when I was out that day). The rock burnt up after an hour or so. I guess it entered our atmosphere with quite a skew angle, otherwise I think it wouldn't have stayed in the sky for so long. I've read that meteors the size of a grain have considerable chances to survive the entry into the atmosphere and reach the earth, if they have the right angle.

[Earniel]

I suppose the determining factor is size. I'm pretty sure that the rocks, floating above our heads, that are large enough to give us a rerun from the dinosaurs can be detected at some distance before they come knocking at our atmosphere. I agree with you that smaller rocks will probably not be detected until they're burning up in the sky.

[Lizra]

Originally posted by Eärniel


Atrazine is effective but it messes with hormones, which is safe to neither humans ór frogs alike IMO. Plus, it's pretty persistant in water and soil.

It's been recently banned completely in Belgium as far as I know. France banned it too 2 years ago. It's under consideration for a European ban last time I heard.

So what do the farmers use to kill weeds now?

[Jonathan]

Originally posted by Eärniel
I'm pretty sure that the rocks, floating above our heads, that are large enough to give us a rerun from the dinosaurs can be detected at some distance before they come knocking at our atmosphere.

Though detecting an ten-mile wide asteroid that's heading for earth isn't worth much unless it's discovered in time. And even rocks of that size are hard to see since they hardly reflect any light at all, so the astronomers might not notice them until they're really close.

[Earniel]

Originally posted by Lizra
So what do the farmers use to kill weeds now?

Other chemical or biological products, I'm sure, some that hopefully will turn out to be less of a burden on the environment and us than the banned ones.

Originally posted by Jonathan
Though detecting an ten-mile wide asteroid that's heading for earth isn't worth much unless it's discovered in time. And even rocks of that size are hard to see since they hardly reflect any light at all, so the astronomers might not notice them until they're really close.

You may be right. I don't know that much of astronomy, I'm afraid.

[Nurvingiel]

Great idea for a thread Lal!

I believe it's a general consensus among conservationists that the 6th mass exctinction has already begun - because of human exploitation of ecosystems.

I'm not going to worry about an asteroid hitting the Earth. It's improbable that a bolloid (a enormous asteroid which would be capable of changing the climate of Earth) would hit the Earth, and we couldn't do anything about it anyway. No, we couldn't blow it up, sit down Bruce Willis.

[Nerdanel]

Originally posted by Nurvingiel
sit down Bruce Willis.

(Exactly my thought )

[Lalaith_Elf]

Originally posted by Nurvingiel
Great idea for a thread Lal!

Thanks Nurv.

I believe it's a general consensus among conservationists that the 6th mass exctinction has already begun - because of human exploitation of ecosystems.

I agree. For example, I think it was last month (I'll have to check), when they revealed that a part of the Amazon rainforest the size of Wales, had been cut down. I know some people don't think that that's a lot when compared to the size of the Amazon, but if it carrys on at that rate then not only will we be destroying this amazing forest and every animal that inhabits it, but we'll be destroying the atmoshphere even more than we already have. We just don't seem to care until it's too late. All people are worried about is money, and how to get the cheapest materials possible. The Government there can't keep up with the amount of illegal logging, if it carries on like this then every year the same amount - and perhaps even more - of the forest will be dissapearing. It's sad. And not only is it spelling the end for those animals who live there but it's showing that if we carry on like we are now, then in time we will destroy everything we need to survive.

I'm not going to worry about an asteroid hitting the Earth. It's improbable that a bolloid (a enormous asteroid which would be capable of changing the climate of Earth) would hit the Earth, and we couldn't do anything about it anyway. No, we couldn't blow it up, sit down Bruce Willis

Some day it'll probably happen. And I think that if it did, theres no point worrying about it. Like you said theres nothing we can do. So if it does happen in our life time (which I sincerely doubt) just sit back and accept it.

[Insidious Rex]

Impact site identified for biggest extinction


12:45 14 May 04

NewScientist.com news service

US geologists claim to have identified a suspect in the Earth's largest and most mysterious mass extinction - a large impact crater off the coast of Australia. However, other geologists are not convinced that the "smoking gun" is even a gun, let alone the lethal weapon.

Luann Becker, of the University of California at Santa Barbara, and colleagues present data in the journal Science that they says reveals a crater rivalling the one blamed for killing the dinosaurs. They say the effects of the newly revealed impact would have devastated the planet 250 million years ago at the end of the Permian period.

Paleontologists have long puzzled over the Permian mass extinction, which killed over 90 per cent of marine species and 50 to 70 per cent of land animals. The discovery of the Chicxulub impact structure in Mexico indicated that a 10-kilometre asteroid wiped out the dinosaurs 65 million years ago and put impacts at the top of the suspect list for the Permian event.

But key evidence was missing, including the iridium-rich fingerprints of an asteroid in sediments and an impact crater. Many researchers came to suspect the gas and dust from massive volcanic eruptions in Siberia were to blame.


Shocked quartz


Evidence for a Permian impact has grown over the last few years, says Doug Erwin, a Smithsonian Institution paleontologist. Researchers have found "shocked" quartz, tiny meteorite fragments and fullerenes in contemporaneous sediments.

But, as with Chicxulub, the first hints of a crater have been revealed by a reexamination of sediment cores drilled by petroleum geologists years earlier. Becker flew to Australia to examine cores from a feature called the Bedout High, which lies in shallow water a couple hundred kilometres off the northwest coast.

She found they were full of shattered rocks called breccia. "It looks just like what you would expect an impact core to look like," she told a NASA press conference on Thursday. In the lab, she found the cores contain glasses that contain higher fractions of silica than volcanic glass, and other evidence that the rocks had been melted by a powerful shock.

Seismic profiles show a central uplift in the Bedout High, and Becker's group argue this is the center of a 200-km crater, filled with later sediments. Dating based on argon isotopes puts the age of the rocks at 250.2 million years, right at the time of the extinction.


Bullseye pattern


However, Christian Koeberl of the University of Vienna, Austria, is not convinced. "There is no unique and unambiguous evidence for impact," he told New Scientist. "The gravity map of Bedout does not show any circular features" like those at Chicxulub.

Although Becker says she found shock-induced flaws in quartz from the cores, Koeberl says the samples shown in the paper are not shocked quartz, and also notes the date comes from only a single sample.

"If it is an impact crater, it's one of the most peculiar things I've ever seen," Jay Melosh of the University of Arizona, US, told New Scientist. The seismic profiles appear typical of continental margins, he says, and the gravity profile lacks the "signature" bullseye pattern expected.

The evidence for a Permian impact is "muddled," says Melosh, leaving perhaps only one thing clear - that more work is needed to reveal the true cause of the biggest loss of life ever seen on Earth.

[Blackheart]

<Waves goodbye to all the monkeys>

Wow. Seems like just yesterday you guys were climbing down from the trees....


Though actually, I'm of the considered opinion that humans are more like cockroaches...

They adapt pretty darned fast. They'll probably find a way to survive long enough to outbreed their resource base again.

I keep thinking that you guys are missing a predator or two...

[BeardofPants]

Yeah, I was reading about that today in the paper. Pretty frickin' cool. Speaking of weird things happening in this region, they've found some crazy fish that breeds by having these tiny little males attaching themselves to giant momma fishies, and gradually becoming permanent fixtures on the exterior of the female. There was this one female who had evidence of six separate male attachments.... Hussy!

*goes off to find story*

News of additional bizarre species was released recently from last year’s deep-sea research voyage by scientists from Australia and New Zealand (and reported in “News of the Weird” in October). The oddest this time was the “deep sea angler fish,” because of its sex life. According to Dr. Mark Norman, curator at Museum Victoria in Australia: “The female is the size of a tennis ball. It has big savage teeth” and “a rod lure off the top of its head with a glowing tip to coax in stupid prey.” The male “looks like a black jellybean with fins.” The mating male bites into the female’s side, drinks her blood and gives her sperm. Their flesh eventually fuse together permanently. Said Norman, “They have found females with up to six males attached.”

http://www.metropulse.com/dir_zine/d...20/t_notw.html

[Blackheart]

^^^^^

Never mind, I think one of the predators just appeared....

[Earniel]

Originally posted by BeardofPants
Yeah, I was reading about that today in the paper. Pretty frickin' cool. Speaking of weird things happening in this region, they've found some crazy fish that breeds by having these tiny little males attaching themselves to giant momma fishies, and gradually becoming permanent fixtures on the exterior of the female. There was this one female who had evidence of six separate male attachments.... Hussy!

*goes off to find story*

http://www.metropulse.com/dir_zine/d...20/t_notw.html

This is not so new. A couple of years ago I saw a specimen of a fish in a museum in (I think) Monaco that was simular. A large flat female fish, about the size of a soupboard with a tiny male attached to her rear-end that had become fused with her and could never get loose again. Talk about taking your commitment seriously.

[Insidious Rex]

whats a soupboard?

[Cirdan]

We've got the snakehead in the Potomac now. It devours every other species it comes in contact with. So much for saving the rockfish.

Human's *are* like cockroaches. Enough will adapt to the next global catastrophe whether it be asteroid, megavolcano, eco-destruction, etc. They eat anything, adapt to any climate, drink fetted water and kill anything that moves.

[Blackheart]

Yeah, conditions would need to change very drastically to kill off ALL the humans.

Of course only a little bit would do lots of damage to agriculture, making mass starvation a distinct possibility.

Soylent green anyone?

[Cirdan]

Originally posted by Blackheart
Soylent green anyone?

What's that made of?

[Earniel]

Originally posted by Insidious Rex
whats a soupboard?

*sniggers* A lovely mix of Dutch and English that means as much as dinner plate, typed by someone who probably was tired and wanted to type that post before her sister claimed the computer. I

[Insidious Rex]

oh. well as long as its bigger then a bread box.