Ancient alteration of seawater chemistry linked with past climate change

Dissolution or creation of huge gypsum deposits changed sulfate content of the oceans

2012-07-24

(Press-News.org) 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 oceans.

"Seawater chemistry is characterized by long phases of stability, which are interrupted by short intervals of rapid change," says geoscientist Ulrich Wortmann of the University of Toronto, lead author of a paper reporting the results and published this week in the journal Science.

"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 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 the collision are exposed in the Zagros Mountains in western Iran.

The dissolution or creation of such massive gypsum deposits changes the sulfate content of the ocean, say the scientists, affecting 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 concentrations correspond with greenhouse [warmer] periods," says Paytan.

"When India and Eurasia collided, it caused dissolution of ancient salt deposits, which resulted in drastic changes in seawater chemistry."

That may have led to the end of the Eocene epoch--the warmest period of the modern-day Cenozoic era--and the transition from a greenhouse to an icehouse climate. "It culminated in the beginning of the rapid expansion of the Antarctic ice sheet," says Paytan.

Canada's Natural Sciences and Engineering Research Council supports Wortmann's research and the U.S. National Science Foundation (NSF) supports Paytan research.

"Abrupt changes in seawater composition are a new twist in our understanding of the links among ocean chemistry, plate tectonics, climate and evolution," says Candace Major, program director in NSF's Division of Ocean Sciences.

To make the discovery, the researchers combined past seawater sulfur composition data collected by Paytan with Wortmann's recent discovery of the strong link between marine sulfate concentrations and carbon and phosphorus cycling.

They found that seawater sulfate reflects huge changes in the accumulation and weathering of gypsum, which is the mineral form of hydrated calcium sulfate.

"While it's been known for a long time that gypsum 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 with climate."

Data used in the research were collected aboard the ocean drillship JOIDES Resolution and through the Integrated Ocean Drilling Program (IODP).

INFORMATION:

IODP is an international research program dedicated to advancing scientific understanding of the Earth through drilling, coring and monitoring the subseafloor.

The JOIDES Resolution is a scientific research vessel managed by the U.S. Implementing Organization of IODP. Texas A&M University, Lamont-Doherty Earth Observatory of Columbia University and the Consortium for Ocean Leadership comprise the implementing organization.

Two lead agencies support the IODP: the U.S. NSF and Japan's Ministry of Education, Culture, Sports, Science and Technology.

Additional program support comes from the European Consortium for Ocean Research Drilling, the Australia-New Zealand IODP Consortium, India's Ministry of Earth Sciences, the People's Republic of China's Ministry of Science and Technology, and the Korea Institute of Geoscience and Mineral Resources.

ELSE PRESS RELEASES FROM THIS DATE:

University of Alberta's designer compounds inhibit prion infection

2012-07-24

(Edmonton) A team of University of Alberta researchers has identified a new class of compounds that inhibit the spread of prions, misfolded proteins in the brain that trigger lethal neurodegenerative diseases in humans and animals. U of A chemistry researcher Frederick West and his team have developed compounds that clear prions from infected cells derived from the brain. "When these designer molecules were put into infected cells in our lab experiments, the numbers of misfolded proteins diminished—and in some cases we couldn't detect any remaining misfolded prions," ...

Tel Aviv University research links childhood obesity to cancer risk

2012-07-24

Parents are increasingly conscious of the dangers of childhood obesity. There is a growing recognition of health problems associated with extra pounds, including the risk of diabetes, heart disease, and joint and muscle pain. New research from Tel Aviv University has revealed another significant reason for children to maintain a healthy weight. Dr. Ari Shamiss and Dr. Adi Leiba of TAU's Sackler Faculty of Medicine and the Sheba Medical Center and their fellow researchers found that obesity in adolescence, defined as a Body Mass Index (BMI) in the 85th percentile and ...

University of Tennessee Space Institute researchers develop laser technology to fight cancer

2012-07-24

Researchers at the Center for Laser Applications at the University of Tennessee Space Institute in Tullahoma have developed a technology that goes on a "seek and destroy" mission for cancerous tumors. They have harnessed the power of lasers to find, map and non-invasively destruct cancerous tumors. Christian Parigger, associate professor of physics, and Jacqueline Johnson, associate professor of mechanical, aerospace, and biomedical engineering, along with Robert Splinter of Splinter Consultants, have developed the invention. The technology uses a femtosecond laser, ...

Aspirin protects against Barrett's esophagus

2012-07-24

Aspirin use appears to reduce the risk of Barrett's esophagus (BE), the largest known risk factor for esophageal cancer, according to a new study in Clinical Gastroenterology and Hepatology, the official clinical practice journal of the American Gastroenterological Association. "The protective effect of aspirin use appears robust because the analyses suggests a dose-response relationship in which high-dose aspirin was significantly associated with decreased Barrett's esophagus risk," said Chin Hur, MD, MPH, of the Massachusetts General Hospital Institute for Technology ...

UConn researchers discover that 'red tide' species is deadlier than first thought

2012-07-24

A University of Connecticut researcher and his team have discovered that a species of tiny aquatic organism prominent in harmful algal blooms sometimes called "red tide" is even deadlier than first thought, with potential consequences for entire marine food chains. Professor Hans Dam and his research group in the school's Department of Marine Sciences have discovered that the plankton species Alexandrium tamarense contains not one but two different types of toxins, one that's deadly to large organisms and one that's deadly to small predators. "If it's killing multicellular ...

Why does vivid memory 'feel so real?'

2012-07-24

Toronto, Canada – Neuroscientists have found strong evidence that vivid memory and directly experiencing the real moment can trigger similar brain activation patterns. The study, led by Baycrest's Rotman Research Institute (RRI), in collaboration with the University of Texas at Dallas, is one of the most ambitious and complex yet for elucidating the brain's ability to evoke a memory by reactivating the parts of the brain that were engaged during the original perceptual experience. Researchers found that vivid memory and real perceptual experience share "striking" similarities ...

Mice have distinct subsystem to handle smell associated with fear

2012-07-24

PROVIDENCE, R.I. [Brown University] — A new study finds that mice have a distinct neural subsystem that links the nose to the brain and is associated with instinctually important smells such as those emitted by predators. That insight, published online this week in Proceedings of the National Academy of Sciences, prompts the question whether mice and other mammals have specially hardwired neural circuitry to trigger instinctive behavior in response to certain smells. In the series of experiments and observations described in the paper, the authors found that nerve cells ...

Survival rates for premature babies in high-level NICUs are better than previously reported

2012-07-24

Premature babies are more likely to survive when they are born in high-level neonatal intensive care units (NICUs) than in hospitals without such facilities, and this benefit is considerably larger than previously reported. The likelihood that an extremely premature baby will survive if born in a high-technology, high-volume hospital unit was already known, but the current study, the largest to date, revealed a stronger effect. Pediatric researchers who analyzed more than 1.3 million premature births over a 10-year span found that the survival benefits applied not only ...

Study finds non-disclosure of HIV serostatus common among India female sex workers

2012-07-24

(Boston) - Researchers from Boston University School of Medicine (BUSM) in partnership with Indian researchers and HIV positive networks groups, have found that in India, non-disclosure of HIV serostatus to sex partners among both HIV-infected female sex workers (FSWs) and HIV-infected clients of FSWs is exceedingly common. These findings currently appear online in the journal AIDS and Behavior. No previous studies in India specifically, and few internationally, have assessed FSWs' and male clients' disclosure of HIV status to sex partners. Disclosure of HIV serostatus ...

New species of ancient rodents hint at what could be world's oldest grasslands

2012-07-24

A paleontological team that includes scientists from the American Museum of Natural History; University of California, Santa Barbara; and Case Western Reserve University has described two ancient species of South American rodents, including the oldest chinchilla, a discovery that substantiates what might be the earliest grasslands in the world. The two new species lived near a chain of volcanoes about 32.5 million years ago in what are now the steep slopes of a river valley in the Chilean Andes. Studies of the teeth of the ancient chinchilla support evidence from other ...

BioCompNet: a deep learning workflow enabling automated body composition analysis toward precision management of cardiometabolic disorders

Nonlinear association between systemic immune-inflammation index and in-hospital mortality in critically ill patients with chronic obstructive pulmonary disease and atrial fibrillation: a cross-sectio

Ancient alteration of seawater chemistry linked with past climate change

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: