Featured Research

from universities, journals, and other organizations

Scientists connect seawater chemistry with ancient climate change and evolution

Date:
July 19, 2012
Source:
University of Toronto
Summary:
Humans get most of the blame for climate change with little attention paid to the contribution of other natural forces. Now, scientists are shedding light on one potential cause of the cooling trend of the past 45 million years that has everything to do with the chemistry of the world's oceans.

This is the Zagros mountain belt in western Iran as seen from the space shuttle Atlantis. The range forms part of the most extensive belt of water-soluble gypsum on Earth, stretching from Oman to Pakistan, and well into Western India. Scientists suggest that the dissolution of ancient salt deposits caused drastic changes in seawater chemistry, which may have triggered long-term global cooling.
Credit: Photo courtesy of NASA

Humans get most of the blame for climate change, with little attention paid to the contribution of other natural forces. Now, scientists from the University of Toronto and the University of California Santa Cruz are shedding light on one potential cause of the cooling trend of the past 45 million years that has everything to do with the chemistry of the world's oceans.

"Seawater chemistry is characterized by long phases of stability, which are interrupted by short intervals of rapid change," says Professor Ulrich Wortmann in the Department of Earth Sciences at the University of Toronto, lead author of a study to be published in Science this week. "We've established a new framework that helps us better interpret evolutionary trends and climate change over long periods of time. The study focuses on the past 130 million years, but similar interactions have likely occurred through the past 500 million years."

Wortmann and co-author Adina Paytan of the Institute of Marine Sciences at the University of California Santa Cruz point to the collision between India and Eurasia approximately 50 million years ago as one example of an interval of rapid change. This collision enhanced dissolution of the most extensive belt of water-soluble gypsum on Earth, stretching from Oman to Pakistan, and well into Western India -- remnants of which are well exposed in the Zagros mountains.

The authors suggest that the dissolution or creation of such massive gyspum deposits will change the sulfate content of the ocean, and that this will affect the amount of sulfate aerosols in the atmosphere and thus climate. "We propose that times of high sulfate concentrations in ocean water correlate with global cooling, just as times of low concentration correspond with greenhouse periods," says Paytan.

"When India and Eurasia collided, it caused dissolution of ancient salt deposits which resulted in drastic changes in seawater chemistry," Paytan continues. "This may have led to the demise of the Eocene epoch -- the warmest period of the modern-day Cenozoic era -- and the transition from a greenhouse to icehouse climate, culminating in the beginning of the rapid expansion of the Antarctic ice sheet."

The researchers combined data of past seawater sulfur composition, assembled by Paytan in 2004, with Wortmann's recent discovery of the strong link between marine sulfate concentrations and carbon and phosphorus cycling. They were able to explain the seawater sulfate isotope record as a result of massive changes to the accumulation and weathering of gyspum -- the mineral form of hydrated calcium sulfate.

"While it has been known for a long time that gyspum deposits can be formed and destroyed rapidly, the effect of these processes on seawater chemistry has been overlooked," says Wortmann. "The idea represents a paradigm shift in our understanding of how ocean chemistry changes over time and how these changes are linked to climate."


Story Source:

The above story is based on materials provided by University of Toronto. The original article was written by Sean Bettam. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ulrich G. Wortmann, Adina Paytan. Rapid Variability of Seawater Chemistry Over the Past 130 Million Years. Science, 20 July 2012: Vol. 337 no. 6092 pp. 334-336 DOI: 10.1126/science.1220656

Cite This Page:

University of Toronto. "Scientists connect seawater chemistry with ancient climate change and evolution." ScienceDaily. ScienceDaily, 19 July 2012. <www.sciencedaily.com/releases/2012/07/120719141802.htm>.
University of Toronto. (2012, July 19). Scientists connect seawater chemistry with ancient climate change and evolution. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2012/07/120719141802.htm
University of Toronto. "Scientists connect seawater chemistry with ancient climate change and evolution." ScienceDaily. www.sciencedaily.com/releases/2012/07/120719141802.htm (accessed September 16, 2014).

Share This



More Fossils & Ruins News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) — Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Museum Traces Fragments of Star-Spangled Banner

Museum Traces Fragments of Star-Spangled Banner

AP (Sep. 12, 2014) — As the Star-Spangled Banner celebrates its bicentennial, Smithsonian curators are still uncovering fragments of the original flag that inspired Francis Scott Key's poem. (Sept. 12) Video provided by AP
Powered by NewsLook.com
Spinosaurus Could Be First Semi-Aquatic Dinosaur

Spinosaurus Could Be First Semi-Aquatic Dinosaur

Newsy (Sep. 11, 2014) — New research has shown that the Spinosaurus, the largest carnivorous dinosaur, might have been just as well suited for life in the water as on land. Video provided by Newsy
Powered by NewsLook.com
Meet Spinosaurus, the First-Known Water Dinosaur

Meet Spinosaurus, the First-Known Water Dinosaur

AFP (Sep. 11, 2014) — Spinosaurus aegyptiacus was adapted for both land and water, and an exhibit featuring a life-sized model, based on new fossils unearthed in eastern Morocco, opens at the National Geographic Museum in Washington on Friday. Duration: 01:02 Video provided by AFP
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:

More Coverage


Ancient Alteration of Seawater Chemistry Linked With Past Climate Change

July 23, 2012 — Scientists have discovered a potential cause of Earth's "icehouse climate" cooling trend of the past 45 million years. It has everything to do with the chemistry of the world's ... read more
from the past week

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