-> My guess is that shifting of mass inside the core is more likely to
-> alter the rotational velocity of the earth than melting water. Even
-> the entire crust of the earth is infinitesimally thin, in relation to
-> the size of the earth, and the spinning, molten nickel-iron core is
-> vastly more massive, and also in motion. At least, that's the current
-> theory as to how the earth's magnetic field is generated. :-)
But how often does mass within the core get suddenly shifted?
A good-sized avalanche or landslide on the surface can move a million
tons or so of material hundreds of metres closer to the axis of
rotation, in a matter of seconds. I think that's enough to make a
measurable difference to the rotation speed.
Earthquakes move far more...
dow
