8 upvotes, 1 direct replies (showing 1)
View submission: Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science
Finally an Earth Science question!! For subduction to occur, there needs to be two plates of Earth's crust with different densities. In other words, one plate has to be denser than the other. The denser plate is the one that sinks and the more buoyant plate is the one that prevails. The newer oceanic crust is simply made of denser rock than the older continental crust, so the oceanic crust sinks.
Comment by SomeAnonymous at 20/07/2022 at 20:30 UTC
2 upvotes, 1 direct replies
I suppose this kind of begs another question though — why do we have this binary "crust density" grouping? Could you not get a portion of crust or tectonic plate which is somewhere in between the two, and behaves accordingly differently to both?