Close X
Sunday, January 12, 2025
ADVT 
International

Revealed: What sets tectonic plates in motion

Darpan News Desk IANS, 18 Sep, 2014 11:15 AM
    The mystery of what kick-started the motion of our earth's massive tectonic plates across its surface has been solved by researchers at the University of Sydney.
     
    There are eight major tectonic plates that move above the earth's mantle at rates of up to 150 millimetres every year and Earth is the only planet in our solar system with such a system in place.
     
    The geological record suggests that until three billion years ago, the earth's crust was immobile so what sparked this unique phenomenon has fascinated geologists for decades.
     
    "We suggest it was triggered by the spreading of early continents and then eventually became a self-sustaining process," said Professor Patrice Rey from the University of Sydney's school of geosciences.
     
    In simple terms, the process involves plates being dragged into the mantle at certain points and moving away from each other at others, in what has been dubbed "the conveyor belt".
     
    Plate tectonics depends on the inverse relationship between density of rocks and temperature.
     
    At mid-oceanic ridges, rocks are hot and their density is low, making them buoyant or more able to float.
     
    As they move away from those ridges they cool down and their density increases until, where they become denser than the underlying hot mantle, they sink and are dragged under.
     
    But three to four billion years ago, the earth's interior was hotter, volcanic activity was more prominent and tectonic plates did not become cold and dense enough to spontaneously sink.
     
    "So the driving engine for plate tectonics did not exist," Rey added.
     
    Instead, buoyant early continents erupted in the middle of immobile plates.
     
    "Our model shows that these early continents could have placed major stress on the surrounding plates. Because they were buoyant they spread horizontally, forcing adjacent plates to be pushed under at their edges," Rey pointed out.
     
    The article appeared in the journal Nature.

    MORE International ARTICLES

    Russia rejects Geneva talks, denies US concerns

    Russia rejects Geneva talks, denies US concerns
    Russia Tuesday ruled out holding a fresh round of talks in Geneva for defusing the Ukraine crisis and refuted the US military's concerns that the activity of long-range warplanes over the Pacific is linked to Ukraine.

    Russia rejects Geneva talks, denies US concerns

    Armed forces uniform for Halloween party lands Indian in trouble

    Armed forces uniform for Halloween party lands Indian in trouble
    An Indian man was fined 2000 dirhams (about $545) by a Dubai court after being spotted in a UAE armed forces officer's dress that he wore to a Halloween party, a report said.

    Armed forces uniform for Halloween party lands Indian in trouble

    South Africa calls for abducted Nigerian girls' release

    South Africa calls for abducted Nigerian girls' release
    The South African government Tuesday appealed to the global community, the African Union (AU) and the Nigerian government to do whatever they can for the release of over 200 girls abducted by Boko Haram, a Nigerian radical group.

    South Africa calls for abducted Nigerian girls' release

    Fall in US unemployment rate fails to enthuse markets

    Fall in US unemployment rate fails to enthuse markets
    Headline economic data releases point out that a gradual and sustained recovery in the US economy is underway.

    Fall in US unemployment rate fails to enthuse markets

    No animal testing for synthetic cannabis: New Zealand PM

    No animal testing for synthetic cannabis: New Zealand PM
    New Zealand's Prime Minister John Key Monday ruled out testing legal drugs, including synthetic cannabis, on animals, days after parliament banned the drugs' sale until proven as low-risk.

    No animal testing for synthetic cannabis: New Zealand PM

    Etihad named best Middle East airline

    Etihad named best Middle East airline
    Etihad Airways, the national airline of the United Arab Emirates (UAE), has been named the Middle East’s Leading Airline for the eighth consecutive year at the World Travel Awards Middle East.

    Etihad named best Middle East airline