Featured Research

from universities, journals, and other organizations

Ancient clams yield new information about greenhouse effect on climate

Date:
August 29, 2011
Source:
Syracuse University
Summary:
Ancient fossilized clams that lived off the coast of Antarctica some 50 million years ago have a story to tell about El Niño, according to new research.

Ancient fossilized clams that lived off the coast of Antarctica some 50 million years ago have a story to tell about El Niño, according to Syracuse University researcher Linda Ivany. Their story calls into question contemporary theories that predict global warming could result in a permanent El Niño state of affairs.

Related Articles


"The clams lived during the early Eocene, a period of time when the planet was as warm as it's been over the last 65 million years," says Ivany, a researcher in the Department of Earth Sciences in SU's College of Arts and Sciences. "We used growth rings in their shells to analyze changes in year-to-year growth rate, and linked that to changes in climate that are characteristic of El Niño today."

The research, "El Niño in the Eocene Greenhouse Recorded by Fossil Bivalves and Wood from Antarctica," is published online in Geophysical Research Letters and is forthcoming in print. Ivany's research team included Thomas Brey of the Alfred Wegener Institute for Polar and Marine Research in Germany as well as researchers from Purdue University, the University of Hawai'i, and the University of Mainz, Germany. The study was funded in part by the National Science Foundation.

The El Niño phenomenon, which occurs every two to seven years, is characterized by unusually warm ocean temperatures in the eastern Equatorial Pacific. El Niño can cause torrential rainfall in Peru, devastating drought in Australia, and generally wreak havoc on global weather. El Niño is the warm phase of a large oscillation in which the surface temperature of the tropical Pacific varies, causing changes in the winds and rainfall patterns. The complete phenomenon is known as the El Niño Southern Oscillation (ENSO). The prevailing theory predicts that rising global temperatures could cause the ENSO to collapse, resulting in permanent El Niño conditions, which could have a major impact on socioeconomic and ecological systems worldwide.

One way to predict the future is to examine past geologic records. The species of clams Ivany's team studied lived to be more than 100 years old during a time when the Antarctic was as warm as modern-day Virginia. Their shells provide a long, continuous record of climate during their lifespan. "Clams, like trees, respond to changes in climate by growing faster or slower," Ivany says. "Therefore, the width of the annual growth rings correlates with environmental variables like temperature or precipitation. We measured the distances between consecutive bands and found two-to-seven-year periodicity in them, which is typically described for El Niño."

The researchers compared the results they obtained from the clams to a similar analysis they did of tree rings from fossilized driftwood they found buried in the same sediments as the clams. "We found the same pattern," Ivany says. "While it might sound counterintuitive, it turns out that the inter-annual climate variations seen in the tropical Pacific today are strongly teleconnected to the Antarctic. This seems to have also been the case 50 million years ago. The good news is that despite the very warm temperatures during the Eocene, the evidence from the clams and tree rings shows that the ENSO system was still active, oscillating between normal and El Niño years. That suggests that the same will be true in our future as the planet warms up again."


Story Source:

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


Journal Reference:

  1. Linda C. Ivany, Thomas Brey, Matthew Huber, Devin P. Buick, Bernd R Schöne. El Niño in the Eocene greenhouse recorded by fossil bivalves and wood from Antarctica. Geophysical Research Letters, 2011; DOI: 10.1029/2011GL048635

Cite This Page:

Syracuse University. "Ancient clams yield new information about greenhouse effect on climate." ScienceDaily. ScienceDaily, 29 August 2011. <www.sciencedaily.com/releases/2011/08/110822102059.htm>.
Syracuse University. (2011, August 29). Ancient clams yield new information about greenhouse effect on climate. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2011/08/110822102059.htm
Syracuse University. "Ancient clams yield new information about greenhouse effect on climate." ScienceDaily. www.sciencedaily.com/releases/2011/08/110822102059.htm (accessed October 25, 2014).

Share This



More Earth & Climate News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Gets Climate Deal, UK PM Gets Knock

EU Gets Climate Deal, UK PM Gets Knock

Reuters - Business Video Online (Oct. 24, 2014) — EU leaders achieve a show of unity by striking a compromise deal on carbon emissions. But David Cameron's bid to push back EU budget contributions gets a slap in the face as the European Commission demands an extra 2bn euros. David Pollard reports. Video provided by Reuters
Powered by NewsLook.com
Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) — Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Raw: Tornado Rips Roofs in Washington State

Raw: Tornado Rips Roofs in Washington State

AP (Oct. 24, 2014) — A rare tornado ripped roofs off buildings, uprooted trees and shattered windows Thursday afternoon in the southwest Washington city of Longview, but there were no reports of injuries. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Fast-Moving Lava Headed For Town On Hawaii's Big Island

Fast-Moving Lava Headed For Town On Hawaii's Big Island

Newsy (Oct. 24, 2014) — Lava from the Kilauea volcano on Hawaii's Big Island has accelerated as it travels toward a town called Pahoa. 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