Continents Split Up at the Same Speed Finger Nails Grow. And That’s Fast.

Jul 28, 2016

By Nicholas St. Fleur

Continents cruise in the slow lane.

Moving just millimeters at a time, it took the ancient supercontinent Pangea hundreds of millions of years to break apart into today’s landmasses. But a study published Tuesday shows that the journey wasn’t always a leisurely drive. When under extreme strain, the tectonic plates hit the throttle and accelerated to speeds 20 times faster than they were traveling before.

“It’s the equivalent of moving around as a pedestrian to moving around in a very fast BMW,” said Dietmar Muller, a geophysicist at the University of Sydney and an author of the paper, which appeared in Nature. “While the continental crust was still being stretched, all of a sudden there was this amazing acceleration, and we didn’t know why.”

After analyzing seismic data from across the world and building a model, Dr. Muller and his team discovered that plates move in two distinct phases: a slow phase and a fast one. During the slow phase, the continental crusts, which can be more than 20 miles thick, are stretched out little by little while remaining connected. But then suddenly, one or both of the continents step on the gas pedal.


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2 comments on “Continents Split Up at the Same Speed Finger Nails Grow. And That’s Fast.

  • @OP – Moving just millimeters at a time, it took the ancient supercontinent Pangea hundreds of millions of years to break apart into today’s landmasses. But a study published Tuesday shows that the journey wasn’t always a leisurely drive.

    Apparently in Oz they are having a problem with that at present!

    http://www.bbc.co.uk/news/technology-36912700
    Australia is to shift its longitude and latitude to address a gap between local co-ordinates and those from global navigation satellite systems (GNSS).

    Local co-ordinates, used to produce maps and measurements, and global ones differ by more than 1m.

    The body responsible for the change said it would help the development of self-driving cars, which need accurate location data to navigate.

    Australia moves about 7cm north annually because of tectonic movements.

    Modern satellite systems provide location data based on global lines of longitude and latitude, which do not move even if the continents on Earth shift.

    However, many countries produce maps and measurements with the lines of longitude and latitude fixed to their local continent.

    “If the lines are fixed, you can put a mark in the ground, measure its co-ordinate, and it will be the same co-ordinate in 20 years,” explained Dan Jaksa of Geoscience Australia. “It’s the classical way of doing it.”

    Because of the movement of the Earth’s tectonic plates, these local co-ordinates drift apart from the Earth’s global co-ordinates over time.

    “If you want to start using driverless cars, accurate map information is fundamental,” said Mr Jaksa.

    “We have tractors in Australia starting to go around farms without a driver, and if the information about the farm doesn’t line up with the co-ordinates coming out of the navigation system there will be problems.”

    The Geocentric Datum of Australia, the country’s local co-ordinate system, was last updated in 1994. Since then, Australia has moved about 1.5 metres north.

    So on 1 January 2017, the country’s local co-ordinates will also be shifted further north – by 1.8m.

    The over-correction means Australia’s local co-ordinates and the Earth’s global co-ordinates will align in 2020.



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  • @OP link – Then, around 200 million years ago the plates entered their fast stage, accelerating for 10 million years until they reached speeds of 20 millimeters per year, which is similar to how fast fingernails grow.

    This does seem quite slow in comparison to Australia’s current N /NE drift of 67mm. per year!



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