Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mother of pearl tells a tale of ocean temperature, depth

17.02.2012
Nacre -- or mother of pearl, scientists and artisans know, is one of nature's amazing utilitarian materials.

Produced by a multitude of mollusk species, nacre is widely used in jewelry and art. It is inlaid into musical instruments, furniture and decorative boxes. Fashioned into buttons, beads and a host of functional objects from pens to flatware, mother of pearl lends a lustrous iridescence to everyday objects.

In recent years, subjecting the material to the modern tools of scientific analysis, scientists have divined the fine points of nacre architecture and developed models to help explain its astonishing durability: 3,000 times more fracture resistant than the mineral from which it is made, aragonite.

Now, in a new report (Thursday, Feb. 16) in the Journal of the American Chemical Society (JACS), scientists from the University of Wisconsin-Madison show that nacre can also be deployed in the interest of science as a hard-wired thermometer and pressure sensor, revealing both the temperature and ocean depth at which the material formed.

"We found a strong correlation between the temperature at which nacre was deposited during the life of the mollusk and water temperature," explains Pupa Gilbert, a UW-Madison professor of physics and chemistry and the senior author of the new JACS report. "All other (temperature) proxies are based on chemical analyses and the relative concentration of different elements or isotopes. This could be our first physical proxy, in which the microscopic structure of the material tells us the maximum temperature and maximum pressure at which the mollusk lived."

The new study was conducted using mother of pearl from modern mollusks, but Gilbert notes that nacre is widespread in the fossil record going back 450 million years. If the techniques used by the Wisconsin group can be applied to fossil nacre, scientists can begin to accurately reconstruct a global record of ancient environments and environmental change.

"If the correlation holds, we would have a thermometer that goes back in time, a paleothermometer of how hot or cold water temperatures were when the nacre formed," says Gilbert.

The material also holds a distinctive signature—the thickness of the nacre layers — for the water depth at which the material was assembled by a mollusk, potentially providing even more insight into environmental conditions of the present and past.

"These are two independent parameters, measured by different aspects of nacre structure," the Wisconsin physicist explains. "The maximum temperature can be measured by how disordered the nacre crystal orientations are, while the maximum pressure can be taken from the thickness of the nacre layers."

Working with UW-Madison graduate student Ian C. Olson, the lead author of the JACS report, Gilbert subjected nacre from eight mollusk species from different environments to a technique capable of mapping the orientation of nacre crystals. From the different shells, they observed uneven thicknesses, widths and angles of the crystalline "bricks" that, together with an organic mortar, are laid down by the mollusk to form mother of pearl.

"We wondered why the shells were so different and concluded that the key parameters to test were the environmental ones, including maximum, minimum and mean annual temperatures as well as maximum and minimum water pressure, which depends on water depth," says Gilbert.

Comparing the structural maps of nacre from the different mollusks and environmental data from the places where the animals were collected, Olson, Gilbert and their collaborators found an extremely high correlation between the microscopic structural characteristics of their nacre specimens and the temperature and pressure data obtained from the various environments where they were collected.

Contributing to the new study were Reinhard Kozdon and John Valley, both of the UW-Madison department of geoscience. The work was funded by the U.S. National Science Foundation.

-- Terry Devitt (608) 262-8282, trdevitt@wisc.edu

Pupa Gilbert | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Earth Sciences:

nachricht NASA eyes Pineapple Express soaking California
24.02.2017 | NASA/Goddard Space Flight Center

nachricht 'Quartz' crystals at the Earth's core power its magnetic field
23.02.2017 | Tokyo Institute of Technology

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>