Paleoclimatology: Explaining the Evidence (2006) | Hacker News Reader

Paleoclimatology: Explaining the Evidence (2006)

earthobservatory.nasa.gov

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My favorite reading on ice ages was the theory that the cycle all started when a tectonic plate rose in Panama and joined north and south America. This blocked the connection of the Atlantic and Pacific oceans which changed global circulation patterns. If that is true, then the way to prevent another glaciation is not to pump carbon into the atmosphere but the nuclear excavation of Panama :-)

> the nuclear excavation of Panama

This has been considered in the past. https://en.wikipedia.org/wiki/Project_Plowshare

Yeah, but the idea here isn't to make a canal for ships, but to have a significant flow between the oceans. My vague memory is that someone suggested a channel 600 feet deep and a mile wide. I don't have a reference for this unfortunately.

(2006 paper)

Related paper from 2010:

https://www.sciencedaily.com/releases/2010/04/100406133707.h...

I found striking the line up of the mediteranean, the black sea and the caspian sea, even further the aral sea and I was wondering if this line was on the aequator before. So if it was, I would wonder, what's the significance of this? Tidal and centrifugal forces influencing the tectonic movement and vice versa, changing water movements influencing the rotation.

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...

[2] https://en.wikipedia.org/wiki/Axial_tilt#Long_term

[2] https://en.wikipedia.org/wiki/Paratethys

> 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.

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.

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

[2] https://www.usna.edu/Users/oceano/pguth/md_help/geology_cour...

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