Featured Research

from universities, journals, and other organizations

Ancient Sea Creatures Serve As Natural Thermometers For Climate Prediction

Date:
December 11, 2002
Source:
Texas A&M University
Summary:
Three-hundred-million-year-old fossil creatures serve as "natural thermometers" and hold clues to Earth's past and future climate, believes Texas A&M University professor Ethan Grossman, who's been studying the fossils for years.

COLLEGE STATION, December 9, 2002 – Three-hundred-million-year-old fossil creatures serve as "natural thermometers" and hold clues to Earth's past and future climate, believes Texas A&M University professor Ethan Grossman, who's been studying the fossils for years.

Related Articles


Mineral deposits in fossilized brachiopod shells allow geochemists to plot changes in sea temperatures over millions of years. These patterns of climate change serve as tests for climate models used to predict global warming.

Grossman researches the isotopic make-up of fossilized brachiopods, sea creatures whose distant relatives – such as lampshells – are still found in today's oceans.

"We drill tiny holes in the fossilized shells, then through isotope-ratio mass spectrometry, analyze the extracted powder for different forms of oxygen," said Grossman of the Department of Geology and Geophysics in the College of Geosciences. "Oxygen always has eight protons but can have different numbers of neutrons. Regular oxygen [O-16] has 8 neutrons in its nucleus, but a nonradioactive isotope with 10 neutrons [O-18] is naturally present in seawater in measureable amounts. The O-18 has a temperature-dependent affinity for the calcium carbonate which forms the shells of many sea creatures.

"By analyzing the ratio of O-18 to regular oxygen in the shells, we can tell the temperature of the ancient seawater. Higher values of O-18 correspond with periods of colder temperatures, and fluctuations in the isotopic ratios of oxygen in the shells over time reflect transitions between icehouse and greenhouse periods in Earth history."

Grossman, along with collaborators David Pollard, Pennsylvania State University; Christopher Scotese, University of Texas at Arlington; and William Hyde, Duke University, presented a paper on their latest analysis of relationships between O-18 distribution and global paleoclimate models at the October annual meeting of the Geological Society of America.

"Oxygen isotope estimates of paleotemperature show good agreement with computerized global climate models for some intervals in the past but not with others," Grossman noted. "We're in the process of investigating possible reasons for this lack of agreement. But study of the patterns of transition during ancient times from periods of cold temperatures, with widespread glaciation, to warmer periods of a more tropical Earth, can lend support to current computer models projections that the Earth has entered another warming period."

Grossman's oxygen isotope research also correlates with studies indicating that increased carbon dioxide in the atmosphere coincides with higher temperatures. This work relies on the measurement of stable carbon isotopes (C-13/C-12) in the shells, a proxy indicator for the carbon cycle.

"Research indicates that drawdown of carbon dioxide, with sequestration of carbon into biomass and sediments, can trigger periods of glaciation," Grossman observed. "Correlating fluctuations of carbon dioxide and carbon and oxygen isotopes in the past may help us better calibrate computer models of future global climate change.

"Our research doesn't prove that increased CO2 is currently causing global warming, but oxygen isotopic measurements of ancient Earth temperatures suggest that this has caused global warming in Earth's past."


Story Source:

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


Cite This Page:

Texas A&M University. "Ancient Sea Creatures Serve As Natural Thermometers For Climate Prediction." ScienceDaily. ScienceDaily, 11 December 2002. <www.sciencedaily.com/releases/2002/12/021211084123.htm>.
Texas A&M University. (2002, December 11). Ancient Sea Creatures Serve As Natural Thermometers For Climate Prediction. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2002/12/021211084123.htm
Texas A&M University. "Ancient Sea Creatures Serve As Natural Thermometers For Climate Prediction." ScienceDaily. www.sciencedaily.com/releases/2002/12/021211084123.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Antarctic Sea Ice Mystery Thickens... Literally

Antarctic Sea Ice Mystery Thickens... Literally

Newsy (Nov. 25, 2014) — Antarctic sea ice isn't only expanding, it's thicker than previously thought, and scientists aren't sure exactly why. Video provided by Newsy
Powered by NewsLook.com
3D Map of Antarctic Sea Ice to Shed Light on Climate Change

3D Map of Antarctic Sea Ice to Shed Light on Climate Change

Reuters - Innovations Video Online (Nov. 24, 2014) — A multinational group of scientists have released the first ever detailed, high-resolution 3-D maps of Antarctic sea ice. Using an underwater robot equipped with sonar, the researchers mapped the underside of a massive area of sea ice to gauge the impact of climate change. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) — A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Yellow-Spotted Turtles Rescued from Trafficking

Yellow-Spotted Turtles Rescued from Trafficking

Reuters - Light News Video Online (Nov. 24, 2014) — Hundreds of Amazon River turtles released into the wild in Peru. Sharon Reich reports. Video provided by Reuters
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