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

Plants that regulate sprouting tackle climate change well

Feeling hot? Make the clouds rain

Earth's extinction rate highly exaggerated: Study

Fingernails glow when you make a call!

Talk to your smart phone to unlock car!

Novel X-ray method for better screening at airports

Why Neanderthals never had brain disorders

Soon, attack drones that can attack from ocean floor

Thinnest ever porous membrane 100,000 times thinner than human hair developed

NASA's LADEE crashes on moon as planned

Sun emits M7-class solar flare

LED bulbs can make your white shirt ineffective!

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