<p>According to this January 2005 NASA JPL News item <a href="https://www.jpl.nasa.gov/news/news.php?feature=716" rel="nofollow noreferrer">NASA Details Earthquake Effects on the Earth</a>, the Three Gorges Dam has slowed down Earth's rotation by <strong>0.06 microseconds per day</strong>. </p>

<p>Having that weight of Earth is an estimate, and so is the volume / weight of water held by the dam and also that these two resulting figures are apart by several orders, how can the resulting deceleration be not only precise, but also calculated at all? The error margin must be much larger, then the result. Or not? How did NASA get the numbers so accurate?</p>

CC BY-SA 4.0
2019-05-12T14:11:11.763Z
Related but different question in Earth Science SE: [Was the filling of the Three Gorges Dam's impact on the Earth's rotation rate detectable?](https://earthscience.stackexchange.com/q/9978/6031)
uhoh
CC BY-SA 4.0
2019-05-12T20:33:32.273Z
Given that there is an answer to this question on Earth Sciences SE and that this question is not about astronomy, I have voted to close this question as off-topic.
David Hammen
CC BY-SA 4.0
2019-05-13T00:20:40.953Z
In that case, I'll vote close too. Earth Science.. - I'll go explore. EDIT: "The duplicate question must exist on Astronomy Stack Exchange",  so cannot vote. Hm :/
marko-36
<earth><rotation><nasa>
How to caclulate the chinese Three Gorges Dam impact on Earth rotation?
marko-36
# How to caclulate the chinese Three Gorges Dam impact on Earth rotation?

(Asked by: username_0 on 2019-05-12)

According to this January 2005 NASA JPL News item [NASA Details Earthquake Effects on the Earth](https://www.jpl.nasa.gov/news/news.php?feature=716), the Three Gorges Dam has slowed down Earth's rotation by **0.06 microseconds per day**.

Having that weight of Earth is an estimate, and so is the volume / weight of water held by the dam and also that these two resulting figures are apart by several orders, how can the resulting deceleration be not only precise, but also calculated at all? The error margin must be much larger, then the result. Or not? How did NASA get the numbers so accurate?

**Tags:** earth, rotation, nasa

> **Comments:**
> **username_1**: Related but different question in Earth Science SE: [Was the filling of the Three Gorges Dam's impact on the Earth's rotation rate detectable?](https://earthscience.stackexchange.com/q/9978/6031)  
> **username_2**: Given that there is an answer to this question on Earth Sciences SE and that this question is not about astronomy, I have voted to close this question as off-topic.  
> **username_0**: In that case, I'll vote close too. Earth Science.. - I'll go explore. EDIT: "The duplicate question must exist on Astronomy Stack Exchange",  so cannot vote. Hm :/  

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