Featured Research

from universities, journals, and other organizations

Cosmic Dust In Ice Cores Sheds Light On Earth's Past Climate

Date:
July 28, 2006
Source:
The Earth Institute at Columbia University
Summary:
Each year nearly 40,000 tons of cosmic dust fall to Earth from outer space. The first successful chronological study of extraterrestrial dust in Antarctic ice has shown that this amount has remained largely constant over the past 30,000 years, a finding that could help refine efforts to understand the timing and effects of changes in the Earth's past climate.

The antarctic ice cap ia a perfect archive for precipitation and dust particles. Therefore even with blue sky you find precipitation of ice particles at Kohnen station in Antartica which can build a halo. Besides terrestrical mineral dust also extraterrestrical dust is deposed. On the top left a extraterrestrical dust particle of a few micrometers size is installed.
Credit: Johannes Freitag & Hubertus Fischer, Alfred Wegener Institute

Each year nearly 40,000 tons of cosmic dust fall to Earth from outer space. Now, the first successful chronological study of extraterrestrial dust in Antarctic ice has shown that this amount has remained largely constant over the past 30,000 years, a finding that could help refine efforts to understand the timing and effects of changes in the Earth's past climate. The same study also used an improved analytical technique to show that dust carried to Antarctica from continental sources changed depending on climate.

The study, which appears in the July 28 issue of the journal Science, involved researchers from the Lamont-Doherty Earth Observatory, a part of The Earth Institute at Columbia University, and the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany. The depth of the core they examined corresponded to the period between 6,800 and 29,000 years before the present day--a span that includes the height of the last glacial period, and the transition to warm conditions similar to today.

The scientists collected particulate matter from the EPICA (European Project for Ice Coring in Antarctica) ice core and measured the concentration of helium-3 (3He), a rare isotope that is plentiful in the sun's solar wind and is carried to Earth imbedded in cosmic dust particles measuring just a few thousandths of a millimeter in diameter. These dust particles carry their exotic helium load to the Earth's surface where they are preserved in the snow and ice of the polar ice caps, among other places.

Because ice cores from the polar caps provide a high-resolution temporal record of the past, the researchers were able to measure fine variations in the rate of cosmic dust accumulation between glacial and interglacial periods as well as the helium isotope characteristics of these rare particles. They found that the accumulation of cosmic dust did not change appreciably as the Earth emerged from the last great Ice Age and entered the current warm period, a fact that is likely to bolster the use of cosmic dust measuring techniques in future climate studies.

In addition, this was the first study to examine both cosmic and terrestrial dust using the same helium-isotope technique. As a result, they also found that the composition of mineral dust particles carried by wind from the southern continents to Antarctica changed considerably as the Earth's climate changed.

"The terrestrial dust coming down on Antarctica during the Ice Age obviously is not the same as that during warm periods," said Gisela Winckler, a Doherty associate research scientist at Lamont-Doherty and lead author on the study. "This may be due to the mineral dust originating from different regional sources or to changes in the process responsible for producing the dust."

The project was supported by the Comer Science and Education Foundation.


Story Source:

The above story is based on materials provided by The Earth Institute at Columbia University. Note: Materials may be edited for content and length.


Cite This Page:

The Earth Institute at Columbia University. "Cosmic Dust In Ice Cores Sheds Light On Earth's Past Climate." ScienceDaily. ScienceDaily, 28 July 2006. <www.sciencedaily.com/releases/2006/07/060727180833.htm>.
The Earth Institute at Columbia University. (2006, July 28). Cosmic Dust In Ice Cores Sheds Light On Earth's Past Climate. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2006/07/060727180833.htm
The Earth Institute at Columbia University. "Cosmic Dust In Ice Cores Sheds Light On Earth's Past Climate." ScienceDaily. www.sciencedaily.com/releases/2006/07/060727180833.htm (accessed October 21, 2014).

Share This



More Fossils & Ruins News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Turns Out Jack The Ripper's True Identity Is Still Unknown

Turns Out Jack The Ripper's True Identity Is Still Unknown

Newsy (Oct. 20, 2014) After testing DNA from a shawl found near one of Jack the Ripper's victims, a scientist said he'd identified the killer. New reports refute the claim. Video provided by Newsy
Powered by NewsLook.com
Fish Fossil Shows First-Ever Sex Was Done Side By Side

Fish Fossil Shows First-Ever Sex Was Done Side By Side

Newsy (Oct. 19, 2014) A 380-million-year-old fish may be the first creature to have copulative sex - and it was side by side with arms linked, like square dancers. Video provided by Newsy
Powered by NewsLook.com
As Sweden Hunts For Sub, "Cold War" Comparisons Flourish

As Sweden Hunts For Sub, "Cold War" Comparisons Flourish

Newsy (Oct. 19, 2014) With Sweden on the look-out for a suspected Russian sub, a lot of people are talking about the Cold War, but is it an apt comparison? Video provided by Newsy
Powered by NewsLook.com
So, Kangaroos Didn't Always Hop

So, Kangaroos Didn't Always Hop

Newsy (Oct. 16, 2014) Researchers believe an extinct kangaroo species weighed 500 pounds or more and couldn't hop. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins