Mapping Armaggedon: Earth's looming tsunamis and mega-quakes ...Alvaro Gonzalez, a researcher of the Center for Mathematical Research in Barcelona, Spain, found that so-called subduction zones -- parts of the Earth where one tectonic plate gets pushed deeper towards the mantle by another -- could trigger a 10.4 magnitude quake.
And they happen on average every 2,000 years. ...
... So when was the last one?