Navigation Links
Ancient sea-levels give new clues on ice ages

International researchers, led by the Australian National University (ANU), have developed a new way to determine sea-level changes and deep-sea temperature variability over the past 5.3 million years.

The findings will help scientists better understand the climate surrounding ice ages over the past two million years, and could help determine the relationship between carbon dioxide levels, global temperatures and sea levels.

The team from ANU, the University of Southampton (UoS) and the National Oceanography Centre (NOC) in the United Kingdom, examined oxygen isotope levels in fossils of microscopic plankton recovered from the Mediterranean Sea, dating back as far as 5.3 million years.

"This is the first step for reconstructions from the Mediterranean records," says lead researcher Eelco Rohling from the ANU Research School of Earth Sciences.

Professor Rohling said the team focused on the flow of water through Strait of Gibraltar, which was particularly sensitive to sea-level changes.

"As continental ice sheets grew during the ice ages, flow through the Strait of Gibraltar was reduced, causing measurable changes in oxygen isotope ratios in Mediterranean waters, which became preserved in the shells of the ancient plankton," he said.

Co-author Gavin Foster from UoS said the research for the first time found long-term trends in cooling and continental ice-volume build-up cycles over the past 5.3 Million years were not the same.

"In fact, for temperature the major step toward the ice ages of the past two million years was a cooling event at 2.7 million years ago," he said.

"But for ice-volume, the crucial step was the development of the first intense ice age at around 2.15 million years ago. Before our results, these were thought to have occurred together at about 2.5 million years ago." Professor Rohling said the findings will help scientists better understand the nature of ice ages and development of coastal sediment.

"The observed decoupling of temperature and ice-volume changes provides crucial new information for our understanding of how the ice ages came about," he said.

"However, there are wider implications. For example, a more refined sea-level record over millions of years is commercially interesting because it allows a better understanding of coastal sediment sequences that are relevant to the petroleum industry.

"Our record is also of interest to climate policy developments, because it opens the door to detailed comparisons between past atmospheric carbon dioxide concentrations, global temperatures, and sea levels, which has enormous value to long-term future climate projections."

The findings have been published in the latest on-line edition of Nature.


Contact: ANU Media Office
Australian National University

Related biology news :

1. Melting glaciers, enough sand to bury London, and ancient ecosystem engineering
2. Ancient civilizations reveal ways to manage fisheries for sustainability
3. Ancient whale species sheds new light on its modern relatives
4. Ancient Egyptian cotton unveils secrets of domesticated crop evolution
5. Ammonites found mini oases at ancient methane seeps
6. New coelacanth find rewrites history of the ancient fish
7. LSU research finds orangutans host ancient jumping genes
8. Whale population size, dynamics determined based on ancient DNA
9. Ancient giant turtle fossil revealed
10. Like curry? New biological role identified for compound used in ancient medicine
11. Tongue analysis software uses ancient Chinese medicine to warn of disease
Post Your Comments:
(Date:5/3/2016)... VILNIUS, Lithuania , May 3, 2016 /PRNewswire/ ... today released the MegaMatcher Automated Biometric Identification ... deployment of large-scale multi-biometric projects. MegaMatcher ABIS can ... and accuracy using any combination of fingerprint, face ... of MegaMatcher SDK and MegaMatcher ...
(Date:4/26/2016)... LONDON , April 26, 2016 ... EdgeVerve Systems, a product subsidiary of Infosys (NYSE: ... a partnership to integrate the Onegini mobile security ... (Logo: ) The ... enhanced security to access and transact across channels. ...
(Date:4/15/2016)... 2016  A new partnership announced today will ... decisions in a fraction of the time it ... high-value life insurance policies to consumers without requiring ... Force Diagnostics, rapid testing (A1C, Cotinine and HIV) ... pressure, weight, pulse, BMI, and activity data) available ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... June 23, 2016 , ... Mosio, a leader in clinical ... Patient Recruitment and Retention Tips.” Partnering with experienced clinical research professionals, Mosio revisits ... tips, tools, and strategies for clinical researchers. , “The landscape of how patients ...
(Date:6/23/2016)... 2016   Boston Biomedical , an industry ... to target cancer stemness pathways, announced that its ... Drug Designation from the U.S. Food and Drug ... including gastroesophageal junction (GEJ) cancer. Napabucasin is an ... cancer stemness pathways by targeting STAT3, and is ...
(Date:6/23/2016)... , June 23, 2016 A person commits a ... crime scene to track the criminal down. An ... Food and Drug Administration (FDA) uses DNA evidence to track ... Sound far-fetched? It,s not. The FDA has increasingly ... support investigations of foodborne illnesses. Put as simply as possible, ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... ... Plate® YM (Yeast and Mold) microbial test has received AOAC Research Institute approval ... of microbial tests introduced last year,” stated Bob Salter, Vice President of Regulatory ...
Breaking Biology Technology: