ELI5: What will continental shift do to cities? Can we prevent it?

An important point that other replies haven't mentioned is that continental crust (which is what practically all land on earth is made of) is almost never subducted (i.e. dragged under another plate) in the first place. Continental crust is less dense than oceanic crust so it 'floats' on top. So even putting aside the fact that we're talking about incredibly slow processes far beyond the time scales of human civilization, if it's subduction you're asking about, it would never happen to cities in the first place.

In terms of what we can do about it, the answer is "not very much, at least with any level of technology that we can imagine". To stop or change plate tectonics you'd have to change the large scale physical or chemical properties of the mantle which is impossible for us in any foreseeable future. The main consequences of plate tectonics that are of relevance to the everyday lives of humans are earthquakes and volcanoes, so the best we can do is remain prepared, avoid building in areas at risk or if that's not possible, make sure our cities are as resilient as possible.

/r/explainlikeimfive Thread