Blueprint for a Dying Earth: what would happen if the world stopped spinning?

Paul Raven @ 28-07-2010

I’m not sure whether I’m a sucker for outlandish “what if?” speculation because I’ve always read science fiction, or whether I read sf because I have some innate speculative itch that I need to scratch. Whichever it may be, this is the sort of thing that pushes a whole lot of my buttons: using modelling software to determine what Planet Earth would look like were it to – for some reason – stop spinning [via BoingBoing].

The lack of the centrifugal effect would result in the gravity of the earth being the only significant force controlling the extent of the oceans. Prominent celestial bodies such as the moon and sun would also play a role, but because of their distance from the earth, their impact on the extent of global oceans would be negligible.

If the earth’s gravity alone was responsible for creating a new geography, the huge bulge of oceanic water—which is now about 8 km high at the equator—would migrate to where a stationary earth’s gravity would be the strongest. This bulge is attributed to the centrifugal effect of earth’s spinning with a linear speed of 1,667 km/hour at the equator. The existing equatorial water bulge also inflates the ellipsoidal shape of the globe itself.

[…]

Today, all three world oceans are connected. This creates a global ocean with basically one sea level. As a consequence of rotational slowdown, the outline of the global ocean would continuously undergo dramatic changes. Equatorial waters would move toward polar areas, initially causing a significant reduction in depth while filling the polar basins that have much less capacity. As regions at high latitude in the northern hemisphere become submerged, the areal extent of the northern circumpolar ocean would rapidly expand, covering the vast lowlands of Siberia and northern portions of North America. The global ocean would remain one unit until the rotation of the earth decreased to the speed at which ocean separation would occur. The interaction between the inertia of huge water bodies and decreasing centrifugal force would be very complicated. As the consequence of steady slowdown of earth’s rotation, the global ocean would be gradually separated into two oceans…

Sure, so it’s pretty unlikely to ever happen… and if it did, speculating about topography would be the last of our concerns, I imagine.

But what if…?

[ As a side note, that’s a great way to virally advertise a piece of software that would otherwise only be of interest to 0.001% of the world’s population. Kudos! ]

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2 Responses to “Blueprint for a Dying Earth: what would happen if the world stopped spinning?”

  1. Robert Koslover says:

    Conservation of angular momentum makes this topic just a bit silly, but I’ll bite. If it were to stop spinning (presumably via a mysterious applied torque yielding a sufficiently slow rate of change, such that the acceleration alone didn’t simply destroy us) then the ocean re-leveling you mention might be less important than the inevitable roasting of the Earth on its sunlit side and bitter freezing on its dark side, given that it would have a year-long day.

  2. Peer Stritzinger says:

    And don’t forget that the Earth itself is mostly liquid and would de-bulge exactly in the same way as the oceans.

    So not much trouble with the water levels, but the de-bulging of the earth will cause some unseen so far earthquakes and volcano eruptions. Of course if we survived that we would probably not the “weather”. Probably would even be worse than a year long day since tidal forces should align us with the sun.