- Also, is proxigean spring tide a special case of perigean spring tide ?
- Are there other kinds of tides other than spring, neap, proxigean spring, and perigean spring tide ?
1$\begingroup$ Would this be better suited for earthscience.stackexchange.com ? $\endgroup$– GrapefruitIsAwesomeFeb 4 at 13:31
A perigean spring tide is a spring tide (one which occurs at new or full moon) that is co-incident with the moon's perigee.
But the moon's motion is not simple. The eccentricity of the moon's orbit varies (between 0.026 and 0.077) due to the effect of the sun's gravity. When the moon's orbit is more eccentric it's perigee is closer to the Earth. The perigee varies between 365400 and 370400 km. This is much less variation than between perigee and apogee (404000–406700 km)
A proxigean spring tide is one that occurs when a new, or full, moon coincides with a perigee that is particularly close to Earth, ie when the moon is about 365400km. Yes. Proxigean spring tides are special type of perigean spring tides.
There's then a lot of nonsense on the internet about colossal tidal waves.
If the moon's motion is complex, then tides are much more complex. They are driven by the moon and sun, but the actual flows are the result of the harmonic resonance of the oceans with the land. This complexity has doubtless resulted in lots of different words for types of tides, but this is beyond astronomy.
A quick Google search reveals that a perigean spring tide occurs when the Moon is at its perigee, while a proxigean spring tide occurs when the Moon is at its perigee and new at the same time (or very nearly so).
2$\begingroup$ The internet is very wrong and confused with lots of people repeating the same wrong information. All spring tides occur when the moon is new or full. A proxigean spring tide can occur when the moon is new or full. $\endgroup$– James KFeb 5 at 10:16
$\begingroup$ @JamesK: Please modify the Wikipedia article accordingly, so that it is factually right. Thanks! $\endgroup$ Feb 7 at 5:15