Eventually, much of the flattened continents will be underwater. Subduction zones will no longer exist, so while earthquakes will still happen every now and then, truly earthshattering events above magnitude 7 or so will be consigned to history.

Will the continents ever sink?

Earth's continental crust, which forms the land we live on, has been slimming down, according to a new estimate. If the slimming rate holds, the continents might disappear into the sea within a couple of billion years.

Can Pangea happen again?

The answer is yes. Pangea wasn't the first supercontinent to form during Earth's 4.5-billion-year geologic history, and it won't be the last. [What Is Plate Tectonics?] ... So, there's no reason to think that another supercontinent won't form in the future, Mitchell said.