Does Lunar Gravity Affect Lake Water Levels?

[rollcast]

Does the grav pull of the moon affect the water level in enclosed lakes?

 

[fzero]

Does the grav pull of the moon affect the water level in enclosed lakes?

Yes it does, but since the change in elevation due to the tides is (approximately) proportional to the average depth of the water, it is very small for most lakes.

 

[AlephZero]

The relatively large amplitude of ocean tides around coastlines is caused by two effects.

1. The interaction of the long-period "tidal wave" with the shallow depth (which is exactly the same as for wind-driven waves, except orders of magnitude slower). This is the main cause of the high tidal range in shallow estuaries.

2. The particular shapes of sea areas (e.g the varying width of the Atlantic and Pacific oceans with latitude) allow standing waves to form with periods close to the main tidal excitiation frequencies. This can cause large variations in the amplitudes of tidal compoents with periods close to 12 and 24 hours. (The idea that "the moon causes two tides per day" is a gross oversimplification of actually happens in many parts of the world).

Most lakes are much too small for either of these effects to be significant, and the magnitude of solar and lunar tides would be of the order of a few mm at most.

 

[rollcast]

Thank guys, was just to settle an arguement