<p>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.</p>
<p>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)</p>
<p>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.</p>
<p>There's then a lot of nonsense on the internet about colossal tidal waves.</p>
<p>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.</p>

CC BY-SA 4.0
2023-02-05T10:11:30.430Z
2023-02-05T12:09:24.477Z
2023-02-05T12:09:24.477Z
James K
<p>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 <strong>and</strong> new at the same time (or very nearly so).</p>

CC BY-SA 4.0
2023-02-05T10:16:07.863Z
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.
James K
CC BY-SA 4.0
2023-02-07T05:15:08.000Z
@JamesK: Please modify the Wikipedia article accordingly, so that it is factually right. Thanks!
Pierre Paquette
CC BY-SA 4.0
2023-02-05T10:14:16.930Z
2023-02-05T10:14:16.930Z
Pierre Paquette
<ul>
<li>Also, is proxigean spring tide a special case of perigean spring tide
?</li>
<li>Are there other kinds of tides other than spring, neap, proxigean
spring, and perigean spring tide ?</li>
</ul>

CC BY-SA 4.0
2023-02-04T13:31:58.023Z
Would this be better suited for https://earthscience.stackexchange.com ?
GrapefruitIsAwesome
<the-moon><earth><tidal-forces>
What's the difference between perigean spring tide and proxigean spring tide?
imdevskp
# What's the difference between perigean spring tide and proxigean spring tide?

(Asked by: username_0 on 2023-02-04)

* 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 ?

**Tags:** the-moon, earth, tidal-forces

> **Comments:**
> **username_1**: Would this be better suited for https://earthscience.stackexchange.com ?  

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## 2 answers

### Answer by username_2 on 2023-02-05. Score: 3 | Accepted answer

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.


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### Answer by username_3 on 2023-02-05. Score: -1

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).

> **Comments:**
> **username_2**: 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.  
> **username_3**: @JamesK: Please modify the Wikipedia article accordingly, so that it is factually right. Thanks!  

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