That is correct, but OTOH there was a 7.3 foreshock two days before the 2011 Tōhoku earthquake. So the only thing we can say for sure is that it is still extre

That is correct, but OTOH there was a 7.3 foreshock two days before the 2011 Tōhoku earthquake. So the only thing we can say for sure is that it is still extremely difficult to predict earthquakes.