Viscous rocks in Earth's core responsible for tectonic plate movement: Aussie study
Source: Xinhua   2018-03-15 11:12:57

CANBERRA, March 15 (Xinhua) -- Researchers from the Australian National University (ANU) said that plate tectonics are responsible for a wide-range of geological phenomena including the movement of continents, the occurrence of volcanoes and earthquakes and mountain-building.

A research team led by ANU School of Earth Sciences experts Ian Jackson and Chris Cline found that flaws has helped to improve the understanding of how rocks in the Earth's core enable the motion of the plates, which in turn regulates the water cycle that makes the planet habitable.

Jackson said that defects in the core allowed hard minerals to change their shape, flowing like a fluid.

"We have found that flaws in the regular atomic packing in the dominant upper-mantle mineral, called olivine, that become more prevalent under oxidizing conditions, substantially reduce the speeds of seismic waves," he said in a media release on Thursday.

"Our new findings challenge a long-held theory that defects involving water absorption in these normally dry rocks could control both their viscosity and seismic properties."

Seismic waves, which are caused by earthquakes, have been compared to computed tomography (CT) scans because of their use in imaging the Earth's deep interior.

In order to make their findings, the ANU team made synthetic specimens similar to upper mantle rocks and subjected them to similar conditions to those of Earth's mantle before measuring their rigidity; the characteristic which controls seismic waves.

"We have the potential to help map the extent of oxidized regions of the Earth's mantle that play such an important role in the chemical evolution of Earth," Jackson said of the research.

Editor: Lifang
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Viscous rocks in Earth's core responsible for tectonic plate movement: Aussie study

Source: Xinhua 2018-03-15 11:12:57
[Editor: huaxia]

CANBERRA, March 15 (Xinhua) -- Researchers from the Australian National University (ANU) said that plate tectonics are responsible for a wide-range of geological phenomena including the movement of continents, the occurrence of volcanoes and earthquakes and mountain-building.

A research team led by ANU School of Earth Sciences experts Ian Jackson and Chris Cline found that flaws has helped to improve the understanding of how rocks in the Earth's core enable the motion of the plates, which in turn regulates the water cycle that makes the planet habitable.

Jackson said that defects in the core allowed hard minerals to change their shape, flowing like a fluid.

"We have found that flaws in the regular atomic packing in the dominant upper-mantle mineral, called olivine, that become more prevalent under oxidizing conditions, substantially reduce the speeds of seismic waves," he said in a media release on Thursday.

"Our new findings challenge a long-held theory that defects involving water absorption in these normally dry rocks could control both their viscosity and seismic properties."

Seismic waves, which are caused by earthquakes, have been compared to computed tomography (CT) scans because of their use in imaging the Earth's deep interior.

In order to make their findings, the ANU team made synthetic specimens similar to upper mantle rocks and subjected them to similar conditions to those of Earth's mantle before measuring their rigidity; the characteristic which controls seismic waves.

"We have the potential to help map the extent of oxidized regions of the Earth's mantle that play such an important role in the chemical evolution of Earth," Jackson said of the research.

[Editor: huaxia]
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