Giant Crater Found: Tied to Worst Mass Extinction Ever

[Eugene]

Giant Crater Found: Tied to Worst Mass Extinction Ever

Robert Roy Britt
Senior Science Writer
SPACE.com Thu Jun 1, 8:00 PM ET

An apparent crater as big as Ohio has been found in Antarctica. Scientists think
it was carved by a space rock that caused the greatest mass extinction on Earth,
250 million years ago.

The crater, buried beneath a half-mile of ice and discovered by some serious
airborne and satellite sleuthing, is more than twice as big as the one involved
in the demise of the dinosaurs.

The crater's location, in the Wilkes Land region of East Antarctica, south of Australia,
suggests it might have instigated the breakup of the so-called Gondwana supercontinent,
which pushed Australia northward, the researchers said.

<snip>

The crater is about 300 miles wide. It was found by looking at differences in density
that show up in gravity measurements taken with NASA's GRACE satellites. Researchers
spotted a mass concentration, which they call a mascon—dense stuff that welled up
from the mantle, likely in an impact.

<snip>

Full article: http://news.yahoo.com/s/space/20060602/sc_space/giantcraterfoundtiedtoworstmassextinctionever

[leftyladyfrommo]

1. Wow.

Did you happen to see the Nova show on the Volcano in Africa that is right over a city of 2 million people?

I can't remember exactly but the fumes from that volcano are kind of the same as all the pollution our industry puts into the sky each day - only many, many times more. The people living there have acid rain so bad that it hurts the skin. And the huge lake has CO2 gas at the bottom of it that could rise to the top of the water and kill everyone very quickly.

Interesting, isn't it. The planet has survived awful things in the past. I just don't think that humans could survive.

[hlthe2b]

4. Can you remember where in Africa? I didn't see it, but interesting..

[elehhhhna]

5. google Cameroon. IIRC that's the place. The gas burping lakes

wiped out whole villages several years ago. Now they have tube vents to the lake bottom to dissipate the gasses.

[leftyladyfrommo]

7. I think that is another lake - where it actually happened and

about 1600 people died. Same phenomena. They mentioned it in the documentary. Can't remember what that effect is called - over something.

This lake is much larger and the effect would be devasting. I'll go see if I can find out names.

[leftyladyfrommo]

8. the volcano is Nyiragongo (in the Congo/Zaire)

the Nova show was "Volcano Under The City" on PBS

Can't find the name of the lake so far - but it is a big lake. And all the CO2 has just settled to the bottom. If that water is disturbed - like by an earthquake or the volcano - all of the CO2 will rise to the surface and just form a huge cloud that moves out away from the lake - over the people. It is odorless and invisible. Would be a huge catastrophe.

It is lake Kivu

One of 3 lakes in the world where there is a possibility of an "overturn." This lake is 2000 times larger than Lake Nyros where the other overturn actually happened.

I guess the CO2 buildup is from lava the actually flows into the lake. The gas builds up overtime.

Interesting. Maybe I should try and do a paper on it.

[elehhhhna]

10. Sorry--Kivu's the one that's been vented by tubes, right?

[leftyladyfrommo]

11. I don't know about the lake - but the volcano has fissures

going out all over the place.

I would love to hve been a geologist. My degree is in anthropology. At the time I guess it didn't matter. Women weren't really allowed in either field.

[Qanisqineq]

2. Fascinating

I am reading a book right now about the mass extinction at the end of the Permian. "When Life Nearly Died: The Greatest Mass Extinction of All Time" by Michael J. Benton. Very interesting.

[formercia]

3. I bet that would have cracked your basement.

ouch!

Remember, we're just a big rock flying through space too. Shit happens.

[mainegreen]

6. So that, timed with the Siberian traps, wow.

It would sure suck to be alive back then.

[leftyladyfrommo]

9. Makes you wonder just how that early life really survived?

During the periods of really active volcano activity the air and water would have been really polluted. Just full of sulphur dioxide and CO2.

Would have been pretty exciting to look at but not a great place to vacation.

[Posteritatis]

12. "Space rock?"

The line to flog that writer, or at least his editor, forms behind me.

Take a number, people!