- #1
errorist
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The tsunami was said to increase the Earths rotational velocity. Did the Earths orbit about the sun also increase?
Did the Earth's Rotation About the Sun Change After the Tsunami?
- Thread starter errorist
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Discussion Overview
The discussion centers on the effects of a tsunami on the Earth's rotation and its potential impact on the Earth's orbit around the sun. Participants explore the relationship between changes in rotational velocity and orbital dynamics, considering both theoretical implications and empirical observations.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant suggests that the tsunami increased the Earth's rotational velocity and questions whether this also affected the Earth's orbit around the sun.
- Another participant explains that the change in the Earth's moment of inertia due to the tsunami was minimal, resulting in a slight increase in rotation that shortens the day by about one millionth of a second, but the effect on orbital velocity would be negligible.
- A different participant provides an estimate that the day was shortened by about 3 microseconds due to the tsunami, noting that tidal braking by the moon counteracts this effect by lengthening days by about 15 microseconds per year.
- One participant seeks clarification on whether the Earth's rotation about the sun sped up or slowed down as a result of the tsunami and by what amount.
Areas of Agreement / Disagreement
Participants express differing views on the significance of the tsunami's impact on the Earth's rotation and its subsequent effect on orbital dynamics. There is no consensus on whether the Earth's orbit changed meaningfully as a result of the tsunami.
Contextual Notes
The discussion includes assumptions about the conservation of angular momentum and the relationship between rotational and orbital dynamics, which may not be fully resolved. The estimates provided are based on reported effects and may depend on specific definitions and measurements.
- #2
Ivan Seeking
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No and yes. The effect on the Earth's 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. 
- #3
Chronos
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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.
- #4
errorist
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In this senerio as to what happened, did the Earths rotation about the sun speed up or slow down and by how much?