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221 points mfiguiere | 2 comments | | HN request time: 0.537s | source
1. vanshg ◴[] No.33698933[source]
> It’s absolutely essential to ensure an open sky and install a solid stationary antenna

What effect, if any, might a major earthquake have on the time calculation?

replies(1): >>33706362 #
2. matheweis ◴[] No.33706362[source]
That’s a very interesting question.

1ns of error equates to ~30cm of error (from speed of light), so:

You might get a couple of ns of error from the initial s and p waves. (Assuming on the order of 50cm displacement)

If you’re on the fault and there is a major displacement (say order of 1-2 meters) there might be several more ns of error.

Practically, this seems to suggest that by the time that displacement from an earthquake would cause a significant loss of clock accuracy (say > 10ns), you most likely have bigger problems to worry about..