# A Ship in an Earthquake?

**URL:** <https://boards.straightdope.com/t/a-ship-in-an-earthquake/825383>\
**Category:** Factual Questions\
**Created:** [December 1, 2018, 7:35am UTC](https://boards.straightdope.com/t/a-ship-in-an-earthquake/825383 "2018-12-01T07:35:03Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Paul\_in\_Qatar](https://avatars.discourse-cdn.com/v4/letter/p/ccd318/32.png) [@Paul\_in\_Qatar](https://boards.straightdope.com/u/Paul_in_Qatar)\
**Post date:** [December 1, 2018, 7:35am UTC](https://boards.straightdope.com/t/a-ship-in-an-earthquake/825383/1 "2018-12-01T07:35:03Z")

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Presume a ship is where it is safest, well out to sea in deep water. Would an earthquake have any impact on it at all? Thinking about it, I suppose even a large earthquake would hardly be noticed.

Am I mistaken?

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**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\
**Post date:** [December 1, 2018, 7:52am UTC](https://boards.straightdope.com/t/a-ship-in-an-earthquake/825383/2 "2018-12-01T07:52:59Z")

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If the earthquake caused an underwater landslide/collapse big enough to cause a [megatsunami](https://en.wikipedia.org/wiki/Megatsunami)it would notice at least, those things can be huge. I’m not sure if it would be actually dangerous far out to sea, though.

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**Author:** ![rat\_avatar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rat_avatar/32/255_2.png) [@rat\_avatar](https://boards.straightdope.com/u/rat_avatar)\
**Post date:** [December 1, 2018, 9:44am UTC](https://boards.straightdope.com/t/a-ship-in-an-earthquake/825383/3 "2018-12-01T09:44:13Z")

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Seismic induced waves have huge wavelengths on the order of 25 miles plus. Due to this they are what are known as a shallow-water wave. In deep water, the amplitude is only a few feet. It would not be noticed by a person or even seen from above in the open ocean due to the other waves.

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**Author:** ![Paul\_in\_Qatar](https://avatars.discourse-cdn.com/v4/letter/p/ccd318/32.png) [@Paul\_in\_Qatar](https://boards.straightdope.com/u/Paul_in_Qatar)\
**Post date:** [December 1, 2018, 10:12am UTC](https://boards.straightdope.com/t/a-ship-in-an-earthquake/825383/4 "2018-12-01T10:12:18Z")

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I thought it had to do with wavelength and water depth, but was a bit unclear on it. Thank you.