Fossil Discovery Shows The Antarctic Icecap is 33.6 million Years Old (Today's Most Popular)
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June 27, 2014

Fossil Discovery Shows The Antarctic Icecap is 33.6 million Years Old (Today's Most Popular)

 

  Erebus

The Antarctic continental ice cap came into existence during the Oligocene epoch, some 33.6 million years ago, according to data from a 2013 international expedition led by the Andalusian Institute of Earth Sciences (IACT)—a Spanish National Research Council-University of Granada joint center. Before the ice covered Antarctica, the Earth was a warm place with a tropical climate. In this region, plankton diversity was high until glaciation 33.6 million years ago reduced the populations leaving only those capable of surviving in the new climate.

Seasonal primary productivity of plankton communities appeared with the first ice. This phenomenon, still active today, influences global food webs. These findings, reported in the journal Science, are based on fossil records in sediment cores at different depths. The study was led by the Andalusian Institute of Earth Sciences, a Spanish National Research Council-University of Granada joint center.

The Integrated Ocean Drilling Program international expedition has obtained this information from the paleoclimatic history preserved in sediment strata in the Antarctic depths. IACT researcher Carlota Escutia, who led the expedition, explains that “the fossil record of dinoflagellate cyst communities reflects the substantial reduction and specialization of these species that took place when the ice cap became established and, with it, marked seasonal ice-pack formation and melting began."

The appearance of the Antarctic polar icecap marks the beginning of plankton communities that are still functioning today. This ice-cap is associated with the ice-pack, the frozen part that disappears and reappears as a function of seasonal climate changes.

As Antarctic summer approaches, this marks the increase in primary productivity of endemic plankton communities. When it melts, the ice frees the nutrients it has accumulated and these are used by the plankton.

Since ice first expanded across Antarctica and caused the dinoflagellate communities to specialize, these species have been undergoing constant change and evolution. However, the IACT researcher thinks “the great change came when the species simplified their form and found they were forced to adapt to the new climatic conditions”.

Pre-glaciation sediment contained highly varied dinoflagellate communities, with star-shaped morphologies. When the ice appeared 33.6 million years ago, this diversity was limited and their activity subjected to the new seasonal climate.

 

          6a00d8341bf7f753ef019102a3acb7970c-500wi

The image above shows A simple dinoflagellate associated with the early Oligocene epoch and found in 33 million year-old sediments.

The Daily Galaxy via University of Granada

Image credit top of page: https://nsidc.org/sites/nsidc.org/files/images//erebus.jpg

Comments

The Antarctic icecap also seems to be growing to enormous proportions.

Consistent with global warming?


http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png

No, no, no Mr. Jones, global warming is science that the guvment has proven time and again! The obamanation said so! Thanks for the link!

Hi guys,

Firstly, this article is about the ice sheet (ice on land), not sea ice. They're different things.

Secondly, increasing Antarctic sea ice was predicted as a result of global warming, due to a change in weather patterns. The fact that recorded Antarctic temperatures have *increased* should tell you that it's consistent.

Thirdly, Daytona: I like your enthusiasm that the USA is at the forefront of climate research, but it just ain't so. You still have politicians incapable of understanding the kind of basic physics that children in most countries understand by age 14. You're way behind the rest of the world.

Never mind though, you'll understand it by 2020. Certainly in Florida...

lol...someone listens to too much talk radio.

SkyDaddy5; I don't listen to radio, and I've no idea what's on American "talk radio" so I don't know what you mean.

Hi seumas,

Thank you kindly.

You state, "Secondly, increasing Antarctic sea ice was predicted as a result of global warming,".

Can you please provide citations for what you say?

This page will give you a good summary as well as links to the papers you require.


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