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Something that has always puzzled me about Pangaea.

If we have a "roughly" spherical mass of solids, aren't two points on opposite sides approximately the same distance from the center of gravity?

If so, how can there be a kilometer or more of ocean above one of them, without it flowing to make the ocean surface the same distance from the center of gravity all around?

https://earthscience.stackexchange.com/questions/9745/how-high-can-a-mountain-possibly-get doesn't seem to address this, since it is talking about a specific peak rather than a wide-spread lopsidedness.

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  • $\begingroup$ Does it make sense for ocean to flow upwards? $\endgroup$
    – Vid
    Commented Jun 6, 2022 at 7:01
  • $\begingroup$ This post seems to be a version of How tall can mountains be on a planet? $\endgroup$
    – Qmechanic ♦
    Commented Jun 6, 2022 at 8:10
  • $\begingroup$ Is it flowing upwards if the land is closer to the center than the water? $\endgroup$
    – WGroleau
    Commented Jun 6, 2022 at 13:28
  • $\begingroup$ @Qmechanic, The link goes to Wikipedia. I don't find an SE question with that exact title, but the one I did find and cite isn't a duplicate $\endgroup$
    – WGroleau
    Commented Jun 6, 2022 at 13:33

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As I recall, the definition of a planet is an object which is large enough to form itself into a sphere (without igniting fusion). That is, gravity can cause a hot interior to flow. Then “sea level” becomes an equipotential surface.

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They're not. Otherwise it would all be covered in a (slightly shallower) layer of water. Where the continent is, the crust is thicker. Also probably around the continent there is slightly more water, as the landmasses have a gravity of their own: A good example are glaciers. If a glacier melts, the sea-level rises on the opposite side of the world, because the glacier's gravity stops pulling the water away.

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  • $\begingroup$ They're not even "approximately" the same distance? I wouldn't expect a thicker crust to make that big a difference. And the difference it would make would be to move the center of gravity further from the ocean on the opposite side. $\endgroup$
    – WGroleau
    Commented Jun 6, 2022 at 17:34
  • $\begingroup$ They are "approximately", but there's also not that much water there. So if the water level (= distance from center of gravity) is equal all around the oceans, then these slight height differences make a difference. $\endgroup$
    – Robbe
    Commented Jun 6, 2022 at 19:17

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