technology-news

Greenland's ice sheet was smaller than today about 3-5,000 years ago

Washington, Nov. 23 : Scientists have said that Greenland's shrunken ice sheet was smaller than today about 3-5,000 years ago.


Jason Briner, PhD, University at Buffalo associate professor of geology, who led the study, said that on land, the atmosphere was warmest between 9,000 and 5,000 years ago, maybe as late as 4,000 years ago while the oceans were warmest between 5-3,000 years ago.

Growing ice sheets are like bulldozers, pushing rocks, boulders and other detritus into heaps of rubble called moraines.

Researchers looked at 250 ancient clams from moraines in three western regions, and discovered that most of the fossils were between 3-5,000 years old.

Briner and his colleagues looked at the structure of clam's amino acids - the building blocks of proteins - in the fossils of ancient clams. Amino acids come in two orientations that are mirror images of each other, known as D and L, and living organisms generally keep their amino acids in an L configuration.

When organisms die, however, the amino acids begin to flip. In dead clams, for example, D forms of aspartic acid start turning to L's.

Because this shift takes place slowly over time, the ratio of D's to L's in a fossil is a giveaway of its age.

Briner's research team matched D and L ratios in 20 Arctic clamshells to their radiocarbon-dated ages to generate a scale showing which ratios corresponded with which ages.

The researchers then looked at the D and L ratios of aspartic acid in the 250 Greenland clamshells to come up with the fossils' ages.

The study has been published in the journal Geology.

--ANI (Posted on 23-11-2013)

technology-news headlines

Potentially habitable Earth-sized planet discovered

2-year-olds 'surprisingly' good at understanding unfamiliar accents

How carnivores evolved into herbivores 300 million years ago revealed

NASA discovers Earth-size planet in 'habitable zone'

New insights on how brain develops memories

Oxygen injections to protect you from air pollution

Sea deposits to build your smart phone!

Google Glass to assist surgeons soon

Soon, floating n-plants that survive tsunami, quakes

Ancient meteors reveal Red Planet's early atmosphere

Global warming to hit your bubbly's taste!

How gut microbes helped our ancestors adapt and survive during Paleolithic era

Quick Links: Goa | Munnar | Pondicherry | Free Yearly Horoscope '2014

Comments

Your e-mail:


Your Full Name:


Type verification image:
verification image, type it in the box

Message:

Back to Top