Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




ICE WORLD
Global Sea-Level Rise At The End Of The Last Ice Age
by Staff Writers
Southampton, UK (SPX) Dec 02, 2010


The researchers brought together about 400 high-quality sea-level markers from study sites around the globe, concentrating on locations far removed from the distorting effects of the past massive ice sheets.

Southampton researchers have estimated that sea-level rose by an average of about 1 metre per century at the end of the last Ice Age, interrupted by rapid 'jumps' during which it rose by up to 2.5 metres per century. The findings, published in Global and Planetary Change, will help unravel the responses of ocean circulation and climate to large inputs of ice-sheet meltwater to the world ocean.

Global sea level rose by a total of more than 120 metres as the vast ice sheets of the last Ice Age melted back. This melt-back lasted from about 19,000 to about 6,000 years ago, meaning that the average rate of sea-level rise was roughly 1 metre per century.

Previous studies of sea-level change at individual locations have suggested that the gradual rise may have been marked by abrupt 'jumps' of sea-level rise at rates that approached 5 metres per century. These estimates were based on analyses of the distribution of fossil corals around Barbados and coastal drowning along the Sunda Shelf, an extension of the continental shelf of East Asia.

However, uncertainties in fossil dating, scarcity of sea-level markers, and the specific characteristics of individual sites can make it difficult to reconstruct global sea level with a high degree of confidence using evidence from any one site.

"Rather than relying on individual sites that may not be representative, we have compared large amounts of data from many different sites, taking into account all potential sources of uncertainty," said Professor Eelco Rohling of the University of Southampton's School of Ocean and Earth Science (SOES) based at the National Oceanography Centre (NOC) in Southampton.

The researchers brought together about 400 high-quality sea-level markers from study sites around the globe, concentrating on locations far removed from the distorting effects of the past massive ice sheets.

Using an extensive series of sophisticated statistical tests, they then reconstructed sea-level history of the last 21 thousand years with a high degree of statistical confidence.

Their analyses indicate that the gradual rise at an average rate of 1 metre per century was interrupted by two periods with rates of rise up to 2.5 metres per century, between 15 and 13 thousand years ago, and between 11 and 9 thousand years ago.

The first of these jumps in the amount of ice-sheet meltwater entering the world ocean coincides with the beginning of a period of global climate warming called the Bolling-Allerod period. The second jump appears to have happened shortly after the end the 'big freeze' called the Younger Dryas that brought the Bolling-Allerod period to an abrupt end.

"Our estimates of rates of sea-level rise are lower than those estimated from individual study sites, but they are statistically robust and therefore greatly improve our understanding of loss of ice volume due to the melting of the ice sheets at the end of the last Ice Age," said lead author Dr Jennifer Stanford of SOES.

"The new findings will be used to refine models of the Earth climate system, and will thus help to improve forecasts of future sea-level responses to global climate change," added Rohling.

The researchers are Jenny Stanford, Rebecca Hemingway, Eelco Rohling and Martin Medina-Elizalde (SOES), Peter Challenor (NOC) and Adrian Lester (The Chamber of Shipping, London). Stanford, J. D., Heminway, R., Rohling E. J., Challenor, P. G., Medina-Elizalde, M. and Lester, A. J. Sea-level probability for the last deglaciation: A statistical analysis of far-field records. Global and Planetary Change (Published online, November 2010).

.


Related Links
University of Southampton
Beyond the Ice Age






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





ICE WORLD
Jack Pine Genetics Support A Coastal Glacial Refugium
Laval, Canada (SPX) Nov 30, 2010
Can a road-trip across eastern North America, ancient ice sheets, and DNA samples unlock the ancestral history of jack pine trees? Julie Godbout and colleagues from the Universite Laval, Quebec, Canada, certainly hoped that driving across northeastern U.S. and Canada to collect samples from jack pine trees would shed some light on how glaciers may have impacted present-day pine genetics. A ... read more


ICE WORLD
Neptec Wins Canadian Space Agency Contract To Develop A New Generation Of Lunar Rovers

Mission to far side of moon proposed

Mining On The Moon Is A Not-So-Distant Possibility

New Analysis Explains Formation Of Lunar Farside Bulge

ICE WORLD
Opportunity Making Progress To Endeavour Crater

Spain Supplies Weather Station For Next Mars Rover

Pits, Flows, Other Scenes In New Set Of Mars Images

IceBite Blog: Remote Control

ICE WORLD
NSS Calls On Congress To Pass NASA Authorization Act Of 2010

Can We Grow Crops On Other Planets

Courting India In Space

China lags in scientific literacy

ICE WORLD
Optis Software To Optimize Chinese Satellite Design

China puts satellite in orbit

Condition Of China's Lunar Probe To Determine Future Application

Tasks For Tiangong

ICE WORLD
Expedition 25 Returns Home

Crews approved for space station mission

Soyuz crew land safely on earth from ISS

New ISS Crew Begins Pre-Flight Exams

ICE WORLD
NASA Sets Coverage For COTS 1 Launch

US private rocket readies key demonstration launch

Hylas-1 In Orbit Brings Europe Broadband From Space

Ariane rocket puts telecom satellites into orbit

ICE WORLD
Super Earth Could Be Steaming Hot Or Full Of Gas

500th 'extrasolar' planet discovered

Planet From Another Galaxy Discovered

First glimpse of a planet from another galaxy

ICE WORLD
German scientist eyes gold mine in rare earths recycling

Apple's iPad has real Xmas rival in Samsung's Galaxy tablet

Estonia's rare earth break China's market grip

India software czar gives 2 bln dlrs of shares to charity




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement