Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Crystallographers explain seismic anisotropy of Earth’s D’’layer

12.05.2006


ETH researchers discovered a very unusual mechanism of plastic deformation in the Earth’s mantle. Furthermore, they have predicted a new family of mantle minerals. These discoveries shed new light on the plastic flow of mantle rocks inside our planet - the process that controls plate tectonics and the associated earthquakes, volcanism, and continental drift.



Plastic flow in the Earth’s mantle is the microscopic process behind plate tectonics and the associated continental drift, volcanism and earthquakes. Seismic anisotropy is the main signature of plastic flow inside the Earth. Its character depends on the properties of Earth-forming minerals. Simulations have provided a new insight that leads to a more consistent picture of the dynamics of our planet. According to seismic observations, the lowermost 150 km of the Earth’s mantle, known as the D"layer, possess many unusual properties. Many of these anomalies were explained by the properties of post-perovskite (Mg,Fe)SiO3, the dominant mineral of the D"layer. Still, it remained difficult to explain the observed strong seismic anisotropy of the D"layer. Now, thanks to metadynamics, a novel simulation methodology, ETH researcher Artem R. Oganov and colleagues have explained these seismic observations. They came up with an unexpected mechanism of plastic deformation of post-perovskite involving the formation of nanoscale slices of the lower-pressure perovskite structure along the (110) planes of post-perovskite. The ETH researchers could show that this mechanism fully explains the observed seismic anisotropy and some geophysical observations are consistent only with this mechanism.

New minerals in the Earth’s mantle


Structures containing slices of the perovskite and post-perovskite structures are not only a result of plastic deformation. Researchers have predicted a whole infinite family of minerals of the same composition, (Mg,Fe)SiO3, built of alternating nanoscale slices of the perovskite and post-perovskite structures. According to quantummechanical calculations of ETH researcher Artem R. Oganov and colleagues, such unusual minerals could become important stable minerals in the Earth’s mantle. Several research groups are now trying to synthesize these predicted minerals. If successful, these attempts will lead to a new mineralogical model of the Earth’s interior. The research results have been published in the end of 2005 in "Nature".

For more information and pictures:
Prof. Artem R. Oganov
ETH Zurich, Laboratory of Crystallography
Phone +4 +41(0)44 632 37 52 or +41(0)43 300 18 73
E-Mail a.oganov@mat.ethz.ch

Anke Poiger | idw
Further information:
http://www.crystal.mat.ethz.ch/research/theory_proj
http://www.nature.com/nature/journal/v438/n7071/full/nature04439.html

More articles from Earth Sciences:

nachricht Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds
25.07.2017 | University of Illinois at Urbana-Champaign

nachricht NASA flights gauge summer sea ice melt in the Arctic
25.07.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds

25.07.2017 | Earth Sciences

The dense vessel network regulates formation of thrombocytes in the bone marrow

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>