Sorry flobadob, all I meant was that besides such events being almost unknown in human history the ones which happen on smaller scales happen randomly and without any advance notice like the tsunamis and plane crashes etc. The media love speculation and even when something is possible due to known circumstances like the Euro falling apart they can't see if and when it will as it's impossible to read the future.
The Canary Island theory has been defused time and time again but still goes on (I am fascinated by such things so have a morbid curiosity to debunk them each time based on what I just explained) and nothing bucks the system of not being able to tell what'll happen ahead.
http://www.iberianatu...rial/megatsunami.html
It was apparently based on a single report some years ago designed to attract funding and since pretty much debunked by actual geologists who said the eruptions were many thousands of years apart and the area is not essentially unstable if there was one. This article is quite balanced but others I've read are absolutely certain it can't happen.