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Earths rotation speeds up?

  1. Jan 2, 2005 #1
    The tsunami was said to increase the Earths rotational velocity. Did the Earths orbit about the sun also increase?
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  3. Jan 2, 2005 #2

    Ivan Seeking

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    No and yes. The effect on the earths rotation was very slight; as reported and as I understand it, the shift in the land mass changed the earth moment of inertia by a tiny, tiny amount. Since angular momentum is conserved, this results in an increased rate of rotation that shortens the day by about one millionth of a second. In principle this would affect our center of mass, hence our distance from the the sun, and ultimately our orbital velocity, but the effect would be so small that it becomes meaningless. In principle, the same thing happens when you stand up or sit down. :biggrin:
  4. Jan 2, 2005 #3


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    According to official estimates, the day shortened by about 3 micro seconds due to earthquake/tsunami effects. The speedup will, however, be shortlived. Tidal braking by the moon lengthens days on earth by about 15 micro seconds per year.
  5. Jan 9, 2005 #4
    In this senerio as to what happened, did the Earths rotation about the sun speed up or slow down and by how much?
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