Some media reports have suggested that this earthquake might be linked to other recent events in the Pacific, implying a chain of quakes in the area that 'jumped' across central America to hit Haiti.

But if the technique can be tried out in other places it might reveal areas now thought safe, precisely because there has not been a recent earthquake, that are actually under threat.

Several quakes have struck the same region in recent days, including a 7.3 magnitude one on Wednesday.