The seabed is difficult to access, but could provide important information on the state of the oceans and even the atmosphere. Underwater earthquakes could also be detected earlier. High time for sensors in submarine cables.https://www.notebookcheck.net/Detecting-tsunamis-surveying-oceans-laying-smart-submarine-cables.814559.0.html
These smart devices will help nothing against those people who attack when they want to attack. Look what happened in Maui, Haiti. It was not a natural cause. It was an attack from a DEW (Directed Energy Weapon). Need another hint for the rabbit hole? Keyword is "blue roofs", which were unaffected by the laser.
What I want to hint here is: the people who own these weapons also have weapons that can produce tsunamis. And if they do use it, it's too late for any "smart device" to prevent the incoming disaster.