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You're right about water influencing the rotation, in a way: increasing drought in the Indian subcontinent and Caspian Sea caused the rotational axis to stop mo

You're right about water influencing the rotation, in a way: increasing drought in the Indian subcontinent and Caspian Sea caused the rotational axis to stop moving towards Hudson Bay and start moving toward the British Isles around 2000[1]. But the Axial tilt of the Earth (and thus the "change in latitude of the Equator") always stays within 2° of 23°.[2] So no, that line was never on the Equator. Those seas were formed by tectonic movement and are not (directly) related to each other. The Caspian and Black Sea are remnants of the Parathetys Ocean[3] while the Mediterrean is a remnant of the Tethys Ocean. The driving forces of plate tectonics aren't completely understood yet, but the Earth's rotational axis (probably) doesn't play a large part. [1] https://www.nasa.gov/feature/nasa-study-solves-two-mysteries-about-wobbling-earth https://www.nasa.gov/feature/nasa-study-solves-two-mysteries... [2] https://en.wikipedia.org/wiki/Axial_tilt#Long_term https://en.wikipedia.org/wiki/Axial_tilt#Long_term [2] https://en.wikipedia.org/wiki/Paratethys https://en.wikipedia.org/wiki/Paratethys

posterboy 9y ago
> The driving forces of plate tectonics aren't completely understood yet, but the Earth's rotational axis (probably) doesn't play a large part. that's a paradox thing to say. at least, it doesn't have to play a large part, anyway the effect could be large and largely chaotic.
- posterboy 9y ago
  PS: I was thinking the closing of the thetys would stop the water circulation through it and that should have a huge effect. What is understood about the driving force of tectonics at all, by the way? Subcutan magma flows are important, I guess.
  - anvandare 9y ago
    I see what you mean by paradox. It's definitely chaotic in that the system loops back on itself, but the main component of tectonics are (supposed to be) mantle cells due to heat difference between the core and the crust.[1] There are Euler poles (also confusingly named poles of rotation - but they're unrelated to the axis of rotation or the poles of the Earth) involved in plate tectonics, but for describing how they move relative to each other.[2] [1] https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget [2] https://www.usna.edu/Users/oceano/pguth/md_help/geology_course/euler_poles.htm https://www.usna.edu/Users/oceano/pguth/md_help/geology_cour...

posterboy 9y ago

> The driving forces of plate tectonics aren't completely understood yet, but the Earth's rotational axis (probably) doesn't play a large part. that's a paradox thing to say. at least, it doesn't have to play a large part, anyway the effect could be large and largely chaotic.

posterboy 9y ago
PS: I was thinking the closing of the thetys would stop the water circulation through it and that should have a huge effect. What is understood about the driving force of tectonics at all, by the way? Subcutan magma flows are important, I guess.
- anvandare 9y ago
  I see what you mean by paradox. It's definitely chaotic in that the system loops back on itself, but the main component of tectonics are (supposed to be) mantle cells due to heat difference between the core and the crust.[1] There are Euler poles (also confusingly named poles of rotation - but they're unrelated to the axis of rotation or the poles of the Earth) involved in plate tectonics, but for describing how they move relative to each other.[2] [1] https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget [2] https://www.usna.edu/Users/oceano/pguth/md_help/geology_course/euler_poles.htm https://www.usna.edu/Users/oceano/pguth/md_help/geology_cour...