Korea is already pretty anomalous. It has three volcanoes and yet is is quite far from a plate boundary. Soo, for example [Jeju island][1]. Maybe the Equilibrium Hivemind has already been?

That region on the map is pretty deep. Some parts need to rise by 1 km to make new land. On the other side, the Yellow Sea has an average depth of less than 50 m. The Philippine plate is going under this region, so it would not be unreasonable for it to rise slowly.

I suppose anything with godlike powers to alter the Earth and everyone's memories can pretty much do what they want. But why? They could just cause the change they want on the other side.


  [1]: https://www.volcanocafe.org/korean-volcanics-the-magic-of-jeju-island/