Subscribe free to our newsletters via your
. 24/7 Space News .




ICE WORLD
North Atlantic signalled Ice Age thaw 1,000 years before it happened
by Staff Writers
London, UK (SPX) Dec 19, 2014


File image.

The Atlantic Ocean at mid-depths may have given out early warning signals - 1,000 years in advance - that the last Ice Age was going to end, scientists report in the journal Paleoceanography. Scientists had previously known that at the end of the last Ice Age, around 14,700 years ago, major changes occurred to the Atlantic Ocean in a period known as the Bolling-Allerod interval.

During this period, as glaciers melted and the Earth warmed, the currents of the Atlantic Ocean at its deepest levels changed direction.

The researchers have analysed the chemistry of 24 ancient coral fossils from the North Atlantic Ocean to learn more about the circulation of its waters during the last Ice Age. They found that the corals recorded a high variability in the currents of the Atlantic Ocean at mid-depths, around 2km below the surface, up to 1,000 years prior to the Bolling-Allerod interval.

The team suggests that these changes may have been an early warning signal that the world was poised to switch from its glacial state to the warmer world we know today, and that the changes happened first at mid-depths.

The study was carried out by researchers from Imperial College London in conjunction with academics from the Scottish Marine Institute, the University of Bristol and Caltech Division of Geology and Planetary Sciences.

Dr David Wilson, from the Department of Earth Science and Engineering at Imperial College London, said: "The world's oceans have always been an important barometer when it comes to changes in our planet. Excitingly, the coral fossils we've studied are showing us that the North Atlantic Ocean at mid-depths was undergoing changes up to 1,000 years earlier than we had expected. The tantalising prospect is that this high variability may have been a signal that the last Ice Age was about to end."

The fossil corals analysed by the team come from a species called Desmophyllum dianthus, which are often around 5cm in diameter and look like budding flowers. They typically only live for 100 years, giving the team a rare insight into what was happening to the ocean's currents during this relatively brief time.

Thousands of years ago they grew on the New England Seamounts, which are a chain of undersea mountains approximately 1000km off the east coast of the US, located at mid-depths 2km beneath the surface. This underwater area is important for understanding the North Atlantic's currents.

While some of the corals analysed by the team come from historical collections, most have been collected by researchers from previous expeditions in 2003 and 2005 to the New England Seamounts. The researchers used deep sea robotic submergence vehicles called Hercules and Alvin to collect the ancient coral fossils.

These ancient coral fossils accumulated rare earth elements from seawater, including neodymium, which leached from rocks on land into the Atlantic Ocean and circulated in its currents, eventually ending up in the coral skeletons. Neodymium isotopes in different regions of the world have specific signatures, created by radioactive decay over billions of years.

The scientists studied the chemistry of the coral fossils to determine where the neodymium isotopes had come from, giving them a glimpse into the circulation of the Atlantic Ocean at the end of the Ice Age.

Since the world's oceans are connected by currents, the next step will see the team integrating the evidence they gathered from the North Atlantic Ocean into a picture of global changes in the mid-depths of oceans around the world. In particular, the team is interested in exploring how the Southern Ocean around Antarctica changed around the same time by analysing neodymium isotopes in a collection of Southern Ocean corals.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
Imperial College London
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








ICE WORLD
Melting Arctic ice, rising temps seen as planet warms
Miami (AFP) Dec 17, 2014
Record high temperatures in Alaska, below average snow cover across the Arctic and excess summer ice melting in Greenland were observed this year by scientists, raising new concerns about global warming. The annual Arctic Report Card, compiled by 63 scientists in 13 countries and updated each year since 2006, was released on Wednesday at the American Geophysical Union meeting in San Francisc ... read more


ICE WORLD
'Shooting the Moon' with Satellite Laser Ranging

Moon Express testing compact lunar lander at Kennedy

UK Plans to Drill Into Moon, Explore Feasibility of Manned Base

Carnegie Mellon Unveils Lunar Rover "Andy"

ICE WORLD
Australian university students aim to generate first 'breathable' air on Mars

Opportunity drives on in no-flash mode

Flying over Becquerel

New idea for transporting spacecraft could ease trip to Mars

ICE WORLD
XCOR Announces Further Progress on XCOR Lynx Spacecraft

NASA releases video of Orion spacecraft re-entry from astronaut's perspective

Russia, US to Cooperate on Orion Spacecraft Modernization

NASA Voyager: 'Tsunami Wave' Still Flies Through Interstellar Space

ICE WORLD
China's Long March puts satellite in orbit on 200th launch

Countdown to China's new space programs begins

China develops new rocket for manned moon mission: media

Service module of China's returned lunar orbiter reaches L2 point

ICE WORLD
NASA, SpaceX Update Launch of Fifth SpaceX Resupply Mission to ISS

Politics no problem, say US and Russian spacefarers

Bright lights: big cities at night

ISS Experiment May Hold Key to Alzheimer's Cause

ICE WORLD
SpaceX postpones launch after rocket 'issues'

SES: Astra 2G ready for december 28 proton launch

US Space Launcher to Get 60 Russian Engines in $1Bln Deal

State Spaceports Receive Federal Funding

ICE WORLD
Kepler Proves It Can Still Find Planets

NASA's Kepler Reborn, Makes First Exoplanet Find of New Mission

Super-Earth spotted by ground-based telescope, a first

Astronomers spot Pluto-size objects swarming about young sun

ICE WORLD
NASA just emailed the space station a new socket wrench

Inmarsat-2 F2 satellite retired after more than 23.5 years of GEO operations

Penn Research Outlines Basic Rules for Construction With a Type of Origami

Dutch Navy LPD getting new radar system




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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 All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.