Featured Research

from universities, journals, and other organizations

Coral links ice sheet collapse to ancient 'mega flood'

Date:
April 3, 2012
Source:
University of Oxford
Summary:
Coral off Tahiti has linked the collapse of massive ice sheets 14,600 years ago to a dramatic and rapid rise in global sea-levels of around 14 meters.

Images of coral off Tahiti sampled for the study
Credit: IODP

Coral off Tahiti has linked the collapse of massive ice sheets 14,600 years ago to a dramatic and rapid rise in global sea-levels of around 14 metres.

Related Articles


Previous research could not accurately date the sea-level rise but now an Aix-Marseille University-led team, including Oxford University scientists Alex Thomas and Gideon Henderson, has confirmed that the event occurred 14,650-14,310 years ago at the same time as a period of rapid climate change known as the Bølling warming.

The finding will help scientists currently modelling future climate change scenarios to factor in the dynamic behaviour of major ice sheets.

A report of the research is published in this week's Nature.

'It is vital that we look into Earth's geological past to understand rare but high impact events, such as the collapse of giant ice sheets that occurred 14,600 years ago,' said Dr Alex Thomas of Oxford University's Department of Earth Sciences, an author of the paper. 'Our work gives a window onto an extreme event in which deglaciation coincided with a dramatic and rapid rise in global sea levels -- an ancient 'mega flood'. Sea level rose more than ten times more quickly than it is rising now! This is an excellent test bed for climate models: if they can reproduce this extraordinary event, it will improve confidence that they can also predict future change accurately.'

During the Bølling warming high latitudes of the Northern hemisphere warmed as much as 15 degrees Celsius in a few tens of decades. The team has used dating evidence from Tahitian corals to constrain the sea level rise to within a period of 350 years, although the actual rise may well have occurred much more quickly and would have been distributed unevenly around the world's shorelines.

Dr Thomas said: 'The Tahitian coral is important because samples, thousands of years old, can be dated to within plus or minus 30 years. Because Tahiti is an ocean island, far away from major ice sheets, sea-level evidence from its coral reefs gives us close to the 'magic' average of sea levels across the globe, it is also subsiding into the ocean at a steady pace that we can easily adjust for.'

The research is part of a large international consortium, the Integrated Ocean Drilling Program (IODP), and the coral samples were obtained by drilling down to the sea floor from a ship positioned off the coast of Tahiti.

What exactly caused the Bølling warming is a matter of intense debate: a leading theory is that the ocean's circulation changed so that more heat was transported into Northern latitudes.

The new sea-level evidence suggests that a considerable portion of the water causing the sea-level rise at this time must have come from melting of the ice sheets in Antarctica, which sent a 'pulse' of freshwater around the globe. However, whether the freshwater pulse helped to warm the climate or was a result of an already warming world remains unclear.


Story Source:

The above story is based on materials provided by University of Oxford. Note: Materials may be edited for content and length.


Journal Reference:

  1. Pierre Deschamps, Nicolas Durand, Edouard Bard, Bruno Hamelin, Gilbert Camoin, Alexander L. Thomas, Gideon M. Henderson, Jun'ichi Okuno, Yusuke Yokoyama. Ice-sheet collapse and sea-level rise at the Bølling warming 14,600 years ago. Nature, 2012; 483 (7391): 559 DOI: 10.1038/nature10902

Cite This Page:

University of Oxford. "Coral links ice sheet collapse to ancient 'mega flood'." ScienceDaily. ScienceDaily, 3 April 2012. <www.sciencedaily.com/releases/2012/04/120403135516.htm>.
University of Oxford. (2012, April 3). Coral links ice sheet collapse to ancient 'mega flood'. ScienceDaily. Retrieved November 22, 2014 from www.sciencedaily.com/releases/2012/04/120403135516.htm
University of Oxford. "Coral links ice sheet collapse to ancient 'mega flood'." ScienceDaily. www.sciencedaily.com/releases/2012/04/120403135516.htm (accessed November 22, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Saturday, November 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Buffalo Residents Digging Out, Helping out

Raw: Buffalo Residents Digging Out, Helping out

AP (Nov. 22, 2014) — Hundreds of volunteers joined a 'shovel brigade' in Buffalo, New York on Saturday, as the city was living up to its nickname, "The City of Good Neighbors." Video provided by AP
Powered by NewsLook.com
Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

AFP (Nov. 21, 2014) — Toyota presented its hydrogen fuel-cell compact car called "Mirai" to US consumers at the Los Angeles auto show. The car should go on sale in 2015 for around $60.000. It combines stored hydrogen with oxygen to generate its own power. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Google Announces Improvements To Balloon-Borne Wi-Fi Project

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Newsy (Nov. 21, 2014) — In a blog post, Google said its balloons have traveled 3 million kilometers since the start of Project Loon. Video provided by Newsy
Powered by NewsLook.com
5 Hot Months, 1 Warm Year And All The Arguments To Follow

5 Hot Months, 1 Warm Year And All The Arguments To Follow

Newsy (Nov. 21, 2014) — The NOAA released statistics Thursday showing October was the fifth month this year with record temps and 2014 will likely be the hottest on record. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins