Interdasting. A better way to accomplish this task would be to flood the hell out of them.
Given that most of the known available water capacity is in underground reservoirs, maybe some other resource could be tapped. Like all that O3 lying on the stratosphere, getting hit with ultraviolet and turning to O2 and O.
O magically joins anything instantaneously. Never to be seen alone. And water is just O2 plus the famous H.
I am sure I heard something about this before. Maybe it can even be done more locally. Just have to be enough that even mountains are filled to the top to make sure no fuckery below emerges later on.
There will probably be some collateral damage. Some serious boating might be needed to help the good folks in the worst hit areas.
Crows are a wonderful bird. Best friend of any sailor. In the absence of electricity and communications they can help find land. Just don't feed them too much meat stuff. They have a tendency to start hoarding it obsessively to forget later where they left it…