[UCANSEE2]

I would think that it is fairly obvious.

The whole planet is growing in size. Has been for billions of years.

That ‘growth’ causes earthquakes as well. If you get on GOOGLE EARTH and look at the DEEP OCEAN RIDGES, you can see the ‘growth lines’ on the seafloor.

[KarlInOhio]

There are matching subduction regions where the crust in pushed down (or goes down naturally and pulls the rest of the plate along) which eliminates sections of the earth's surface.

[Upstate NY Guy]

DEEP OCEAN RIDGES, you can see the ‘growth lines’ on the seafloor.

kinda like this?

[redangus]

The new mantle being produced at the mid ocean ridges is recycled at the subduction zone in the deep ocean trenches. It works somewhat like the conveyor belt at your local grocery store. It bubbles up at the ridge, solidifies, rides across the molten magma and then dives back under the adjoining plate at the subduction zone and is re-melted only to be pushed back up at the ridge(or as volcanic magma).