Japanese researchers believe they may be closer to predicting an earthquake, but it hasn't come without criticism.
After 20 years research of quakes with a magnitude of 5.5 or higher, University of Tokyo academics say they've found a link between high tide, and large earthquakes.
They say it could indicate a greater likelihood of events following a new, or full moon.
But University of Melbourne Associate Professor Mark Quigley warns it's a hypothesis and not an absolute finding.
He says there are abnormalities in their results, and the 5.7 magnitude earthquake that occurred near Christchurch in February is a good example of this; it didn't occur near any major tidal events.