[miniTAX]

.but NOT independent of convection, right? And temperature differences would promote convection, right?
temperature difference triggers convection only if high temperature is at the bottom. In oceans, high temperature is at the top because the heat source (sun) is at the top, so there is no convection in oceans. It's like trying to boil a pot of water from the top, there will be no convection cell. There is though localized mixing from wind, conveyor belts currents...

[alexander_busek]

temperature difference triggers convection only if high temperature is at the bottom. In oceans, high temperature is at the top because the heat source (sun) is at the top, so there is no convection in oceans. It's like trying to boil a pot of water from the top, there will be no convection cell. There is though localized mixing from wind, conveyor belts currents...

I knew someone was gonna come with that sort of argument - that's why I explicitly pointed out that water reaches its max. density at +4.5 °C.

Thus, under certain circumstances, insolation (incident solar radiation) would result in massive convection.

E.g.: A body of saltwater (3.5% salt concentration - like the ocean) with a more-or-less uniform temperature of, say, +1 °C (maybe +3 °C at the bottom, maybe -0.5 °C at the top)... Sun comes out from behind the clouds and heats the surface. Surface temperature rises to +4.5 °C. Surface water is now denser than the rest of the body of water. Surface water therefore sinks. Voilà: Convection!

Regards,

[EEGator]

https://www.nationalgeographic.org/media/deep-sea-hydrothermal-vents/

https://www.nationalgeographic.org/encyclopedia/magma/

What about thermal vents and decompression melting?

[5th MEB]

Would undersea volcanoes count as fire at the bottom of the oceanic pot?