Science
Related: About this forumEarth's tectonic plates have doubled their speed
SO MUCH for slowing down as you age. Earth's tectonic plates are moving faster now than at any point in the last 2 billion years, according to the latest study of plate movements. But the result is controversial, since previous work seemed to show the opposite.
If true, the result could be explained by another surprising recent discovery: the presence of more water within Earth's mantle than in all of the oceans combined.
Plate tectonics is driven by the formation and destruction of oceanic crust. This crust forms where plates move apart, allowing hot, light magma to rise from the mantle below and solidify. Where plates are being pushed together, the crust can either rise up to form mountains or one plate is shoved under the other and is sucked back into the mantle.
The planet's inner heat powers plate tectonics. That heat is ebbing away as Earth ages, and this was expected to slow plate motion. A study last year by Martin Van Kranendonk at the University of New South Wales in Sydney, Australia, and colleagues measured elements concentrated by tectonic action in 3200 rocks from around the world, and concluded that plate motion has been slowing for 1.2 billion years.
Now Kent Condie, a geochemist at the New Mexico Institute of Mining and Technology in Socorro and his colleagues have used a different approach and concluded that tectonic activity is increasing. They looked at how often new mountain belts form when tectonic plates collide with one another. They then combined these measurements with magnetic data from volcanic rocks to work out at which latitude the rocks formed and how quickly the continents had moved.
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http://www.newscientist.com/article/mg22329843.000-earths-tectonic-plates-have-doubled-their-speed.html
Louisiana1976
(3,962 posts)NRaleighLiberal
(59,940 posts)Warpy
(110,900 posts)The crust is just the skin that forms over a pot of boiled milk. It's very thin and very mobile.
I have no idea why it's speeding up but it will likely usher in a new period of vulcanism.
That is not going to be pleasant.
nilram
(2,879 posts)By 0.00003465% in the coming year. At least, that's if they're going to increase at the rate that it took to for them double over the last 2,000,000,000 years.
dickthegrouch
(3,151 posts)the 'rides' will get bumpier