Persistent near-tropical warmth on the Antarctic continent during the early Eocene epoch

The warmest global climates of the past 65 million years occurred during the early Eocene epoch (about 55 to 48 million years ago), when the Equator-to-pole temperature gradients were much smaller than today1, 2 and atmospheric carbon dioxide levels were in excess of one thousand parts per million by volume

Nature Magazine
Here is a conundrum..If the Antarctic coast was tropical and is now part of the antarctic sea bed that means the water levels have risen since 52 million years ago. Where did that water come from?? It didnt come from the arctic or antarctic because these were tropical.

So HOW did the water level rise? What if the Arctic and Antarctic as they currently exist were not always part of the north and south poles? According to ice core samples taken from the Arctic and Antarctic we can roughly date back the ice sheets on the north and south poles to about 2.6 million years ago.

So before that we can assume there was no ice on the north and south. Still begs the questions of where the water came from..

Here we present a well-dated record of early Eocene climate on Antarctica from an ocean sediment core recovered off the Wilkes Land coast of East Antarctica. The information from biotic climate proxies (pollen and spores) and independent organic geochemical climate proxies (indices based on branched tetraether lipids) yields quantitative, seasonal temperature reconstructions for the early Eocene greenhouse world on Antarctica. We show that the climate in lowland settings along the Wilkes Land coast (at a palaeolatitude of about 70° south) supported the growth of highly diverse, near-tropical forests characterized by mesothermal to megathermal floral elements including palms and Bombacoideae. Notably, winters were extremely mild (warmer than 10 °C) and essentially frost-free despite polar darkness,

So does anybody know where the water came from??

reply to post by TiM3LoRd


Possibly from comets, containing water, that came from the Oort cloud and ended up smashing into the Earth's oceans...

This is just a wild guess.

So HOW did the water level rise? What if the Arctic and Antarctic as they currently exist were not always part of the north and south poles?

I think Antarctica and the Arctic ocean are still pretty much where they were (at the poles) during the Eocence.

Sea levels weren't lower during the Eocene. The sediment which formed the seabed washed off of the surface of the land.
jgs.geoscienceworld.org...

The water came from the ice sheets at previous poles.

Lack of sunlight at the poles allows for ice to form. In theory, the Earth should have equal sized ice caps at both poles. However, tectonic shifting, meteor impacts, among other factors play into our tilted axis rotation we currently experience.

Were it not for the Northern hemisphere's pronounced tilt, the landmass that is Antarctica would have significantly less ice, and perhaps even habitable coasts.

If I get your premise and going on what I learned doing a big college report on Lake Vostok, I'd say Antarctica is fairly easily explained. It's the largest water thief in history, to be simple. I think as it shifted and moved into the position we see it now, from where evidence does show it was tropical at one time....it rained and snowed and it never gave it back in thaws.

So, disturbing as it may sound to someone in a Beach house for theories, the water level may actually be artificially low by a large degree because land moved to catch what might have been open water like the North pole before that? Just my idea.... (Of course, I live far inland and at some elevation. )

Originally posted by IEtherianSoul9
reply to post by TiM3LoRd

 

Possibly from comets, containing water, that came from the Oort cloud and ended up smashing into the Earth's oceans...

This is just a wild guess.

So you are saying over the last 50 million years extra terrestrial bodies of water have deposited enough water to raise sea levels as much as is currently observable? I find that hard to believe. We are bombarded by meteorites with far more frequency than we go through tails of comets. By that reasoning the land mass would increase at a greater rate than the water level.

reply to post by TiM3LoRd

Sea levels during the Eocene were higher than they are today. The water has been captured in glacial ice.

Originally posted by TiM3LoRd

Originally posted by IEtherianSoul9
reply to post by TiM3LoRd

 

Possibly from comets, containing water, that came from the Oort cloud and ended up smashing into the Earth's oceans...

This is just a wild guess.

So you are saying over the last 50 million years extra terrestrial bodies of water have deposited enough water to raise sea levels as much as is currently observable? I find that hard to believe. We are bombarded by meteorites with far more frequency than we go through tails of comets. By that reasoning the land mass would increase at a greater rate than the water level.

I dont really think this is the case however it would only take one really good size comet or groups of comets. We also know that water levels in different areas have risen and fallen...

Originally posted by Phage
reply to post by TiM3LoRd

 

Sea levels during the Eocene were higher than they are today. The water has been captured in glacial ice.

Im not denying that. I understand that the levels have risen and fallen based on the ice accumulations on the poles. What had me stumped was the fact they mentioned evidence of forests on the coasts and that these fossils were discovered in the sea bed.

We show that the climate in lowland settings along the Wilkes Land coast (at a palaeolatitude of about 70° south) supported the growth of highly diverse, near-tropical forests characterized by mesothermal to megathermal floral elements including palms and Bombacoideae.

These are some pretty big trees and I was asking how they would have been deposited on the sea bed and turned into fossils. I can understand them turning into fossils on land and then the sea level rising to cover it.

reply to post by TiM3LoRd

The information from biotic climate proxies (pollen and spores) and independent organic geochemical climate proxies (indices based on branched tetraether lipids) yields quantitative, seasonal temperature reconstructions for the early Eocene greenhouse world on Antarctica.

www.nature.com...

Originally posted by Phage
reply to post by TiM3LoRd

 

The information from biotic climate proxies (pollen and spores) and independent organic geochemical climate proxies (indices based on branched tetraether lipids) yields quantitative, seasonal temperature reconstructions for the early Eocene greenhouse world on Antarctica.

www.nature.com...

I see, so these findings are based on spores and pollen samples NOT actual fossils of trees and other biological samples.

Originally posted by TiM3LoRd

Originally posted by Phage
reply to post by TiM3LoRd

 

The information from biotic climate proxies (pollen and spores) and independent organic geochemical climate proxies (indices based on branched tetraether lipids) yields quantitative, seasonal temperature reconstructions for the early Eocene greenhouse world on Antarctica.

www.nature.com...

I see, so these findings are based on spores and pollen samples NOT actual fossils of trees and other biological samples.

......... based on spores and pollen samples,not fossils.

Think you need to check yourself on that one.

The most important finds are based on spores and pollen.

It is a pretty incredible place and the only unexploited land on Earth. A massive land mass though, and all frozen in time. They do find quite a bit where the rock and other methods come to expose what is there to be seen.

Antarctica today is a cold, inhospitable desert; however, in the more distant past, the climate was much warmer. Abundant finds of fossil leaves and wood point to the existence of extensive forestation in earlier geological periods, even to within a few degrees of latitude of the South Pole itself. Dinosaurs, and later, marsupial mammals once roamed across its surface.

British Antarctic Survey

I'd wouldn't suggest exploring now because I don't think our society could handle doing it without destroying so much down there. Someday though, I think there are volumes to be found beneath the ice.

Originally posted by Wrabbit2000
It is a pretty incredible place and the only unexploited land on Earth. A massive land mass though, and all frozen in time. They do find quite a bit where the rock and other methods come to expose what is there to be seen.

Antarctica today is a cold, inhospitable desert; however, in the more distant past, the climate was much warmer. Abundant finds of fossil leaves and wood point to the existence of extensive forestation in earlier geological periods, even to within a few degrees of latitude of the South Pole itself. Dinosaurs, and later, marsupial mammals once roamed across its surface.

British Antarctic Survey

I'd wouldn't suggest exploring now because I don't think our society could handle doing it without destroying so much down there. Someday though, I think there are volumes to be found beneath the ice.

Quite the frozen time capsule we have there. No wonder there are so many research scientist from all parts of the world there.

reply to post by TiM3LoRd


One bite at a time...

Antarctica is different that the arctic. The former is a land mass and was in the region on what is today the south pole during much of the Eocene. The later is not a land mass. If all the ice melted at the north pole, it would be open ocean. Sure, a few islands here and there but not a continent like Antarctica.

Second bite...

With regard to sea level, MSL does fluctuate on the sea side AND the land side. Land masses, especially their edges subside and rebound all the time. Plus we are talking the Eocene, millions of years ago. Any evidence is usually extrapolate in interpolated and subject to deviation.