Secrets of Antarctica's fossilised forests (BBC)

[eppur_se_muova]

By Howard Falcon-Lang
Royal Holloway, London

It may be hard to believe, but Antarctica was once covered in towering forests.

One hundred million years ago, the Earth was in the grip of an extreme Greenhouse Effect.

The polar ice caps had all but melted and rainforests inhabited by dinosaurs existed in their place.

These Antarctic ecosystems were adapted to the long months of winter darkness that occur at the poles, and were truly bizarre.

But if global warming continues unabated, could these ancient forests be a taste of things to come?
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more: http://www.bbc.co.uk/news/science-environment-12378934

[WillParkinson]

1. See, it happened 100 million years ago!

It's all natural and it's not man-made. Everyone worries for nothing.

:sarcasm:

[Mojorabbit]

10. This is exactly what I hear from family members. nt

[Orrex]

2. I blame the Elder Things

[Tyrs WolfDaemon]

4. It's all thanks to those damn Frost Giants fighting the Fire Giants

However, having them fight each other is better than them fighting us...:evilgrin:

[MisterP]

3. augh! Elder Things

--er, frolicking in the woods...

[jpak]

6. Tekeli-li! Tekeli-li!

:scared:

[XemaSab]

5. This is the best article ever

:)

[hunter]

7. I wonder if any animals hibernated?

There might be animals that slept all summer, and other animals that slept all winter.

[XemaSab]

11. Or maybe some of the dinosaurs just went into torpor?

:shrug:

[NickB79]

12. Some appear to be specialized to live in the dark

http://home.alphalink.com.au/~dannj/ecenvir.htm

"Studies of the brain cast of Leaellynasaura show that this small dinosaur had extremely well developed optic lobes, the parts of the brain associated with vision (the bump on the lower left of the picture, see below). The skull also indicates that these tiny dinosaurs had quite large eyes. This suggests that some hypsilophodontids may have remained active throughout the long dark winters, which would explain the absence of lag lines in the bones. "

[OnlinePoker]

8. 100 mya Antarctica was further north.

If I remember my grade 12 geology, the Antarctic plate started its southward journey about 200 million years ago and got to its present location 40-60 mya so could have had forests without any greenhouse effect.

[happyslug]

9. The following only shows 150 mya and 80 mya, but till 50 mya Australia and Antarctica were connected

http://www.uwgb.edu/dutchs/EarthSC102Notes/102PTEarthHist.htm

80 million years ago:


150 years ago:


From the above two maps, it is clear that most of Antarctica was already within what we call the Antarctic Circle, but part of it was attached to Australia till about 50 mya.

Present theory says Antarctica had no permanent ice till about 20 million years ago (mya). The Antarctic probably had snow and ice during the winter, but none in the summer.

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

Present theory also holds that the CO2 has a cycle. CO2 in the air is slowly absorbed into the ocean via river currents. The River deposit the CO2 nuggets onto the ocean floor where they law till a tectonic plate forces them into the mantel. Once in the Mantel the C02 flows till it comes to a Volcano and is released into the air. Once in the air, Plants absorb the CO2 to make "sugar" which is then deposited into the ground when the plant dies (or into the ground when an animal who ate that plant dies). These deposits are then driven into rivers by rain fall and the whole system starts all over again.

This system is not perfect. During the time that the Indian Subcontinent was into the Indian Ocean heading to Asia, it flows over a huge amount of Carbon deposited into the Indian Ocean. This lead to a slow increase in world wide temperatures till the Indian Plate hit the Asiatic Plate. When that collusion occurred you had a slow drop in Carbon going into the mantel and with that slow drop, you also had a slow drop in world wide temperatures starting about 50 mya, leading to the world getting cold enough to permit permanent ice in Antarctica by 20 mya.

More on Plate tectonics and CO2:
http://woodstown.org/ACS/resources/ec/ch12/act4.pdf
http://www.geo.umass.edu/climate/papers2/deconto_tectonics&climate.pdf