Navigation Links
Greenland's shrunken ice sheet: We've been here before
Date:11/22/2013

echnique the scientists developed involves dating fossils in piles of debris found at the edge of glaciers.

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

Because glaciers only do this plowing when they're getting bigger, logic dictates that rocks or fossils found in a moraine must have been scooped up at a time when the associated glacier was older and smaller.

So if a moraine contains fossils from 3,000 years ago, that means the glacier was growing and smaller than it is today 3,000 years ago.

This is exactly what the scientists saw in Greenland: They 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.

The finding suggests that this was the period when the ice sheet's western extent was at its smallest in recent history, Briner said.

"Because we see the most shells dating to the 5-3000-year period, we think that this is when the most land was ice-free, when large layers of mud and fossils were allowed to accumulate before the glacier came and bulldozed them up," he said.

Because radiocarbon dating is expensive, Briner and his colleagues found another way to trace the age of their fossils.

Their solution was to look at the structure of 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.

Knowing this, Briner's research team matched D and L ratios in 20 Arctic
'/>"/>

Contact: Charlotte Hsu
chsu22@buffalo.edu
716-645-4655
University at Buffalo
Source:Eurekalert  

Page: 1 2 3

Related biology news :

1. Chemotherapy before radiotherapy for testicular cancer could reduce long-term side-effects
2. Hot flashes before menopause? It can happen
3. Invasive species: Understanding the threat before its too late
4. What you eat before surgery may affect your recovery
5. Researchers discover gateway in nucleus has a second important job no one noticed before
6. Researchers attack HIVs final defenses before drug-resistant mutations emerge
7. Dark matter made visible before the final cut
8. New method for uncovering side effects before a drug hits the market
9. Grant funded to improve mothers nutrition before pregnancy and impact on baby
10. Stopping flies before they mature
11. A mother’s nutrition--before pregnancy--may alter the function of her children’s genes
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Greenland's shrunken ice sheet: We've been here before
(Date:10/16/2014)... severe respiratory tract infections and worldwide claims the ... VIB and Ghent University have succeeded in developing ... virus infection. , Xavier Saelens (VIB/UGent): "We ... way for the development of a novel approach ... suffering in numerous small children and elderly people." ...
(Date:10/15/2014)... book ,Models of Life, is a non-traditional biophysics textbook ... The book is a journey of discovery into biological ... life and biological regulation. It is about how our ... communication between the billions of cells in an organism. ... relationships between principles, which can be found on both ...
(Date:10/15/2014)... 44th Rosenstiel Award for Distinguished Work in Biomedical Science ... mechanisms of genomic instability and its implications for the ... alumnus to win the Rosenstiel Award; the first, Rod ... is the Charles A. Janeway Professor of Pediatrics and ... investigator at the Howard Hughes Medical Institute at Boston ...
Breaking Biology News(10 mins):New perspectives for development of an RSV vaccine 2New book about life as seen from physics 2Brandeis awards 44th Rosenstiel Award to pioneering geneticist Fred Alt 2
... Some parents of children with autism evaluate facial expressions ... a way that is strikingly similar to autistic patients ... Piven of the University of North Carolina at Chapel ... Institute of Technology. Piven, Adolphs and colleague ...
... in individuals of Asian descent increases the risk of ... the August Journal of Lipid Research . In ... this rare variant for apolipoprotein A-V had extremely high ... Apolipoprotein A-V is a recently discovered lipid-binding protein that ...
... BET DAGAN, ISRAEL - Table grapes are subject to serious ... the vine to dinner tables around the world. Mold and ... reduce grape quality during shipping and storage in retail produce ... are one way of ensuring that consumers get fresh, appealing ...
Cached Biology News:UNC, Caltech research finds further evidence for genetic contribution to autism 2UNC, Caltech research finds further evidence for genetic contribution to autism 3Genetic variant increases triglyceride levels in Asian-Americans 2Fresh from the grapevine to the table 2
(Date:10/25/2014)... Los Angeles, California (PRWEB) October 23, 2014 ... VDRM ), a specialty pharmaceutical company devoted to ... pursuing out-licensing partnerships in 2015. , ViaDerma has ... method, which allows for rapid mass transfer of ... into the body to provide immediate localized therapy. ...
(Date:10/25/2014)... Va. (PRWEB) October 24, 2014 ... the nation’s leading nonprofit authority on the ... healthcare information exchange, announces its appointment of four ... Workgroup. The workgroup leaders include:, , ... ,     Erik Pupo, Specialist Leader, Deloitte Consulting ...
(Date:10/25/2014)... 24, 2014 A new way to ... pitfalls of current skin grafting technologies, it also speeds ... The method, outlined in the October issue of STEM ... deep skin injuries that result from severe burns and ... the skin’s regenerative elements. These wounds heal by contraction, ...
(Date:10/25/2014)... , Oct. 24, 2014  RegeneRx Biopharmaceuticals, Inc. (OTCBB: ... presented at the Fourth International Symposium on Thymosins in ... Italy.  "When thymosin beta 4 (TB4) ... into the peritoneal cavity in a rodent model of ... throughout the brain parenchyma (the functional tissue of the ...
Breaking Biology Technology:ViaDerma, Inc. Announces Plans to Pursue Out-Licensing Partnerships in 2015 2ViaDerma, Inc. Announces Plans to Pursue Out-Licensing Partnerships in 2015 3WEDI Appoints Four New Security and Privacy Workgroup Co-chairs 2New engineering method shows promise for faster healing, more cosmetically appealing skin grafts 2New engineering method shows promise for faster healing, more cosmetically appealing skin grafts 3Researchers Report Thymosin Beta 4 Crosses Blood-Brain Barrier In Animal Stroke Model 2
... International,Corporation (Nasdaq: PRXL ) announced today that its ... Common Stock, which will be effected by,means of a ... will receive one additional share of,Common Stock for each ... of,February 22, 2008. The additional shares will be distributed ...
... Incorporated,(Nasdaq: GPRO ) announced today that Carl ... chief operating officer, effective March 1, 2008., ... 2007 as executive vice,president and chief operating officer. ... and development, manufacturing, and,sales and marketing., "Carl,s ...
... Feb. 11 BioSpace, the leading biotech,job board ... over 800,biotechnology and pharmaceutical job seekers to the ... CA., The BioSpace Career Fair attracted a ... diagnostics career,candidates from around southern California. The event ...
Cached Biology Technology:PAREXEL International Announces 2-For-1 Stock Split 2PAREXEL International Announces 2-For-1 Stock Split 3Carl Hull Named President and Chief Operating Officer of Gen-Probe 2Carl Hull Named President and Chief Operating Officer of Gen-Probe 3BioSpace Career Fair in San Diego Draws Record Number of Bioscience Candidates 2
... PureLink PCR Purification Kits provide rapid ... enzymes, short-failed PCR products, and salts from ... bind/wash/elute procedure:, provides two Binding Buffer ... bp* , can be performed in either ...
... PCR Cloning Kit offers the fastest ... cloning of blunt-end PCR products amplified ... includes the linearized and topoisomerase I-activated ... ligations without ligase (1). The pCR-Blunt ...
2.0 GHz Compaq Computer with 512 MB RAM, 32 MB AGP Graphics Card, 40 GB Hard Drive, 1 Serial Port & Open PCI Slot, Windows 2000 OS, MS Office, CD Read/Writer and 18 Flat Panel Monitor...
Blot Paper 7 x 8.5cm semi-dry western blots (order number RB-400)...
Biology Products: