Earth's Rotation Slows and Atlas Shrugs

Did you feel the Earth move?  Or rather, did you feel it slow a bit under your feet?  It has. 

            In what is not quite so cataclysmic an occurrence as one might think, the Earth is experiencing its fourth year of slow down.  The rotational speed of our planet is not a fixed thing.  The Earth wobbles on its axis, our magnetic poles switch polarities, the amount of solar wind that reaches and reacts with our planet increases and decreases.   All these natural phenomena have occurred in the past and will occur again.  Right now, it is time for our planet to slow a bit.

            While this may not mean that buildings are toppling there are still consequences.  First, geophysicists do measure the rotational speed of our planet very precisely.  The variations occur in milliseconds.  That is the minuscule cause, the effect, on the other hand, is magnified.  Like the distance between two lines diverging from a single point, the distance gets bigger, the farther you go from the point of origin.  Here is the A-B-C of it:

a.      The Earth slows down…

b.      The slower rotation reduces our bulge at the equator…

c.       The tectonic plates, on which our crust floats, don’t shrink, as the equator does, and the edges of them become squeezed…

d.      Added stress on the plate boundaries causes earthquakes, volcanic activity and general geological mayhem.

            The result of all of this is that 2018 is stacking up to be a big year for earthquake activity.  This earthquake correlation with slower rotation has been tentatively established with studies going back to 1900.  Every 25-30 years the Earth’s rotation slows for a period of around five years.  The last year of this cycle begins the uptick in earthquakes. 

            With the cause and effect set, the only remaining question is what causes this periodic slow down.  Here there is less data and more supposition.  The hypothesis that seems to have a bit more purchase than others places the blame on the earth’s outer core.  We know that the earth has three main parts: the crust, the mantle and the core.  Think of a golf ball, cut down the middle (these proportions, by the way, will not be accurate, but only a graphic approximation).  The skin of the ball is like our crust—thin and tough.  The middle of the ball is like the mantle, thick and pliable.  The core is like a liquid center.  The liquid spins faster than the exterior, so it forms a directional ballast.

            The Earth’s core has both an inner and outer portion.  The outer core is super-hot liquid metal and moves slowly in currents under the mantle which is, by comparison, solid.  There is some thought that the outer core sometimes gets hung up on the mantle---slowing, stopping and confusing direction.  This both alters the magnetic field and the rotation rate.  The Earth slows, ever so slightly.

            For those of you hoping for some divine revelation in these problems, or at least Karma wrecking her ugly vengeance on a politically or morally corrupt people, the answer turns out to be a crueler mistress than either choice.  It is physics.  It is mass in motion.  It is weight, momentum, inertia and entropy.  The music of the spheres is mathematical. 

            Learn a little science.  It helps you keep the faith.