Atlantis Online
March 28, 2024, 07:41:00 pm
Welcome, Guest. Please login or register.

Login with username, password and session length
News: 'Europe's oldest city' found in Cadiz
http://mathaba.net/rss/?x=566660
 
  Home Help Arcade Gallery Links Staff List Calendar Login Register  

Antarctica Plant Life Once Thrived On Continent, New Research Finds

Pages: [1]   Go Down
  Print  
Author Topic: Antarctica Plant Life Once Thrived On Continent, New Research Finds  (Read 157 times)
0 Members and 93 Guests are viewing this topic.
Ice Age Wanderer
Superhero Member
******
Posts: 2170



« on: June 18, 2012, 08:29:43 pm »

Antarctica Plant Life Once Thrived On Continent, New Research Finds

Posted: 06/18/2012 6:39 pm Updated: 06/18/2012 6:39 pm




Antarctic Plant Life
An artist's interpretation of what middle Miocene Antarctica might have looked like. Shrubs and even stunted trees would have grown along the coast.

By: LiveScience Staff

The few plants that live in Antarctica today are hardy hangers-on, growing just a few weeks out of the year and surviving poor soil, lack of rain and very little sunlight. But long ago, some parts of Antarctica were almost lush.

New research finds that between about 15 million and 20 million years ago, plant life thrived on the coasts of the southernmost continent. Ancient pollen samples suggest that the landscape was a bit like today's Chilean Andes: grassy tundra dotted with small trees.

This vegetated period peaked during the middle Miocene, when atmospheric carbon dioxide levels were around 400 to 600 parts per million. (Today, driven by fossil fuel use, atmospheric carbon dioxide has climbed to 393 parts per million.)

As a result, global temperatures warmed.

Antarctica followed suit. During this period, summer temperatures on the continent were 20 degrees Fahrenheit (11 degrees Celsius) warmer than today, researchers reported June 17 in the journal Nature Geoscience.

"When the planet heats up, the biggest changes are seen toward the poles," study researcher Jung-Eun Lee, a scientist at NASA's Jet Propulsion Laboratory, said in a statement. "The southward movement of rain bands made the margins of Antarctica less like a polar desert and more like present-day Iceland." [Ice World: Amazing Glaciers]

NASA researchers, along with scientists from the University of Southern California and Louisiana State University, collected long cores of sediment from below Antarctica's Ross Ice Shelf. Within the sediment, they found plant-leaf wax, an indication of ancient vegetation. The cores also contained pollen and algae.



pollengrain120618
A pollen grain from modern-day southern beech trees that grow in New Zealand. Ancient Antarctica would have hosted similar trees.

An analysis of the leaf wax provided a record of the water taken up by the plants when they lived. Researchers could then track variations in the hydrogen molecules in the water, called isotopes. Because isotopes vary over time and over certain environmental conditions, these variations allowed the researchers to reconstruct what the climate would have looked like when this water fell as rain.

If current carbon emissions continue as they are, atmospheric carbon is set to reach middle Miocene levels by the end of the century. The northern Antarctic Peninsula has already warmed by 4.5 degrees F (2.5 degrees C) over the last 50 years, and satellite views reveal melting ice shelves.

The ancient Antarctic sediment could provide a vision of what is to come, said study leader Sarah Feakins, an earth scientist at the University of Southern California.

"Just as history has a lot to teach us about the future, so does past climate," Feakins said in a statement. "What this record shows us is how much warmer and wetter it can get around the Antarctic ice sheet as the climate system heats up."

Follow LiveScience on Twitter @livescience. We're also on Facebook & Google+.
Report Spam   Logged

Share on Facebook Share on Twitter



Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by EzPortal
Bookmark this site! | Upgrade This Forum
SMF For Free - Create your own Forum
Powered by SMF | SMF © 2016, Simple Machines
Privacy Policy