Monday, May 13, 2013

Ice-free arctic may be in our future

UMassAmherst Office of News & Media Relations: Analyses of the longest sediment core ever collected on land in the Arctic, recently completed by an international team led by Julie Brigham-Grette of the University of Massachusetts Amherst, provide “absolutely new knowledge” of Arctic climate from 2.2 to 3.6 million years ago and show that with estimated atmospheric carbon dioxide (CO2) similar to today’s levels, the Arctic was very warm, with no ice sheets.

“While existing geologic records from the Arctic contain important hints about this time period, what we are presenting is the most continuous archive of information about past climate change from the entire Arctic borderlands. As if reading a detective novel, we can go back in time and reconstruct how the Arctic evolved with only a few pages missing here and there,” says Brigham-Grette.

Results of analyses that provide “an exceptional window into environmental dynamics” never before possible were published this week in Science and have “major implications for understanding the pacing and context of how the Arctic transitioned from a forested landscape without ice sheets to the ice- and snow-covered land we know today,” she adds.

Their data come from analyzing sediment cores collected in the winter of 2009 from under ice-covered Lake El’gygytgyn, the oldest deep lake in the northeast Russian Arctic. “Lake E” was formed 3.6 million years ago when a huge meteorite hit the Earth and blasted out an 11-mile (18 km) wide crater. It has been collecting sediment layers ever since. Luckily for geoscientists, it lies in one of the few Arctic areas not eroded by continental glaciers, so a thick, continuous sediment record was left remarkably undisturbed. Cores from Lake E reach back in geologic time nearly 30 times farther than Greenland ice cores that cover the past 140,000 years.

“One of our major findings is that the Arctic was very warm in the Pliocene [~ 5.3 to 2.6 million years ago] when others have suggestedatmospheric CO2 was very much like levels we see today. This could tell us where we are going in the near future. In other words, the Earth system response to small changes in carbon dioxide is bigger than suggested by earlier models,” the authors state....

NASA image showing the location of Lake El'gygytgyn

7 comments:

Anonymous said...

Pretty section of content. I just stumbled upon your site and in
accession capital to assert that I get actually enjoyed account your blog posts.
Anyway I will be subscribing to your feeds and even I achievement you access
consistently quickly.

my web blog :: www.explorethecapabilities.com

Anonymous said...

I loved as much as you'll receive carried out right here. The sketch is tasteful, your authored material stylish. nonetheless, you command get bought an shakiness over that you wish be delivering the following. unwell unquestionably come more formerly again since exactly the same nearly very often inside case you shield this hike.

My blog post: singing Instructor

Anonymous said...

I really love your site.. Pleasant colors & theme.
Did you build this web site yourself? Please reply back as I'm trying to create my very own blog and would like to learn where you got this from or what the theme is called. Cheers!

Visit my web blog; how to tattoo ebook

Anonymous said...

Simply want to say your article is as astounding.
The clearness in your post is just cool and i could assume you're an expert on this subject. Well with your permission allow me to grab your feed to keep updated with forthcoming post. Thanks a million and please keep up the gratifying work.

Here is my webpage: asbestos lawyers baltimore

Anonymous said...

Its such as you read my mind! You appear to understand so much about this, like you wrote the
e-book in it or something. I feel that you can do with a few percent
to drive the message home a little bit, but other
than that, that is fantastic blog. A fantastic read.
I will certainly be back.

My web page Blues piano made easy

Anonymous said...

Appreciate this post. Will try it out.

Feel free to surf to my webpage ... violin lessons For Children

Anonymous said...

Thanks for sharing such a good opinion, piece of
writing is fastidious, thats why i have read it completely

my web blog :: Voice lessons singing
my web page: best singing lessons online