What are the solutions, in your opinion, if an earthquake occurs? Or in other words, the best solution if you are in an area active in earthquakes and tsunamis.
Redundancy and off site storage.
A stainless steel metal plate of sufficient thickness will likely survive an earthquake or a building collapsing on it without significant damage. Jameson Lopp has tested many such devices under a 20 ton hydraulic press, and devices which are simply steel plates hold up very well under such conditions (any device with moving parts such as tiles, not so much). However, having your metal plate survive is not much use to you if it is buried under several tons of rubble and you will never find it again. Similarly if you are in a tsunami region, your metal plate will survive just fine, but is no use to you if it is buried under rubble a kilometer away from where you stored it and you will never see it again.
So you need redundancy. This means more than one back up, so if one back up is lost, you have others you can rely on. And these other back ups need to be geographical separate, so if a natural disaster affects your city/town/village, you have a back up in a different city/town/village which is unaffected.