>water belongs to everyone
Careful with that statement, anon. People can easily take that the wrong way and demand to have free water from the water companies.
>"fresh water was discovered underneath the ocean"
That premise drove the plot for Stephen Baxter's 2008 disaster book "Flood." (A decent book, BTW).
en.wikipedia.org/wiki/Flood_(Baxter_novel)
That would be Cumbre Vieja on La Palma in the Canary Islands. That threat of a the volcano's possible collapse causing a mega-tsunami has been known since at least 2000, possibly later.
It's curious though if a nuclear weapon could trigger the collapse of the mountain and cause a mega-tsunami.
en.wikipedia.org/wiki/Cumbre_Vieja