How would plate tectonics work on these planets?
Posted: 16 May 2017 20:17
I'm especially wondering about the tidally locked planet...
Watsisname wrote:My guess would be about the same as on any other terra. Plate tectonics is based on mantle convection, which is slow and does not care a whole lot about the planet's rotation rate.
Wikipedia wrote:External sources of planetary heat (namely, radiation from a planet’s host star) can have drastic effects on geodynamic regime. With all other variables held constant, an Earth-sized exoplanet with a surface temperature of 273 K will evolve over its geological lifetime from a plate tectonic regime, to episodic periods of plate tectonics interspersed with stagnant lid geodynamics, to a terminal stagnant lid phase as interior heat is exhausted. Meanwhile, a “hot” planet (759 K surface temperature) under the same initial conditions will have an amorphous surface (due to lithospheric yield stress being constantly exceeded) to a stagnant lid as interior heat is exhausted, with no plate tectonics observed.
Planets closer than 0.5 astronomical units from their star are likely to be tidally locked; these planets are expected to have drastically different temperature regimes on their “day” and “night” sides. When this scenario is modeled, the day side displays mobile lid convection with diffuse surface deformation flowing toward the night side, while the night side has a plate tectonic regime of downwelling plates and a deep mantle return flow in the direction of the night side. A temperature contrast of 400 K between day and night sides is required to create such a stable system