What would happen to the oceans if the earth stopped rotating

[pne]

Interesting thought experiment on what would happen to the oceans if the earth slowed down its rotation until, after a few decades, it stopped rotating completely, with several maps.

Short version: since the earth “bulges” a bit at the equator and it’s centrifugal force that keeps the water level high there, if rotation stopped, water would move “down” under the force of gravity and collect around the poles. You’d end up with flooded Canada and Siberia and a huge circum-equatorial continent.

Interesting!

Comments

[steorra]

I saw that too, and there was one thing I wondered if their model took account of, and if it was mentioned, I didn't see it.

Once the northern and southern basin got separated, water in some quantity would still transfer between them by weather patterns and precipitation, right? Might that have an overall effect raising one and lowering the other over time?

[pauamma]

Hard to say. I suspect a large share of the convection patterns would be day-side to night-side, resulting in something like a moonsoon climate. Any redistribution across the equator would be likely either near the Andes mountain range (because they're kinda slanted from north-south) or near the Kiribati, because that's where the lowest point of the dividing mountain belt is).

[xaea]

you always post such fascinating stuff, pne.

[sollers]

In the comparatively short time while there was still liquid water all over the planet, surely there would still be some equatorial bulge from the moon's gravity and a significant one on the day side from the sun's gravity?

[ewx]

They do mention gravitation from other bodies and say it’s not a significant effect. AFAIK what matters is not the force exerted at the near surface in isolation, but the difference between the forces exerted across the diameter the earth; which isn’t very much because the bodies involved are so far away. My back-of-the-envelope calculation suggests it’s a smaller effect from the sun than the moon - the sun is much more massive, but it’s also much further away.

[pne]

The sun’s pull is essentially what leads to tides, isn’t it; and even in the Bay of Fundy, that’s not more than 17 metres: a pittance when compared to the relative diameters at the equator and the poles.

[ewx]

By exactly the same calculation the lunar involvement in the tides will be stronger than the solar.

[steorra]

The major tidal effect comes from the moon; a significant secondary effect comes from the sun.

When the effects of the sun and moon are aligned, the tides are more extreme, and it's called "spring tides", and when the effects of the sun and moon are at cross purposes, the difference between low and high tides is less extreme, and it's called "neap tides".

But yeah, it's only a matter of a few metres.