Can local gravitational variations be measured from tidal asymmetry?

  • Level: High School 
  • Thread starter Thread starter JeffEvarts
  • Start date Start date
  • Tags Tags
    gravity local tides
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
Sign up Log in
3 replies · 2K views
JeffEvarts
Messages
74
Reaction score
7
It occurs to me that it might be possible to determine a local value of G by observing the tides over a long-ish period. Tide height might be distributed as a normal curve, but it might have a measurable deviance. I wouldn't expect a left/right offset of the X coordinate based on G(local) , but perhaps an asymmetry across the mean X. Seems like a likely candidate for a paper, anyway. Anyone got a pointer to a study/thesis/paper on tides-vs-local-G?

-Jeff Evarts
 
Physics news on Phys.org

Discussion

I do not like your chances.
Tidal changes in sea level are predicted by the synthesis of well over one hundred Fourier terms of solar and lunar terms. I believe that there are too many confounding variables, such as movement of the sand on the sea floor, wind, atmospheric pressure and ocean water temperature.

Only with a very accurate pendulum clock can you see tidal variation in the period of the pendulum. That is how you identify the best pendulum clocks.

Would you like a reference to a book on tide prediction?
 
  • Like
Likes   Reactions: russ_watters
Can you better describe your idea?

Get a copy of; "Manual of Harmonic Analysis and Prediction of Tides" by Paul Schureman, 1971.
From archive at: https://archive.org/details/manualofharmonic00schu

Find a copy of; "Limitations of High Precision Tidal Prediction" by B. Ducarme, and any other papers from that authors.

Don't forget that the Earth has a solid tide. The reference mark on the rock will also rise and fall as you measure the height of the sea level tide.
Because of changing ionospheric conditions, GPS has too much vertical variation to establish an accurate bench mark reference level.
 
Baluncore, thank you kindly for your thorough, but not dissmissive replies. All technical forums need more of your ilk.

-Jeff Evarts