Predicting large earthquakes is not as simple as looking to the moon or watching the pet cat.
A post online predicting an earthquake either side of November 14 due to the supermoon has gained traction.
But scientists have debunked on November 6.
This is despite his prediction coming true at 12.02am yesterday when a 7.5 earthquake struck near Culverden.
Napier astronomer Gary Sparks said Mr Gray's prediction was just a pure coincidence.
"There was no way the upcoming proximity of the moon caused the quake, we get four or five in a year. It is just a poppycock."
Geonet public information specialist Caroline Little agreed with Mr Sparks, saying there was no correlation between the supermoon and the quake.
"Quake probability has been studied for years and if it was that easy to spot we would have figured it out by now. It has been an active period for quakes since 2009 so it is just a coincidence it hit today."
Ms Little said magnitude seven earthquakes had been happening regularly in the Southern Hemisphere but often did not happen in populated areas.
"Research suggests that magnitude one or two quakes could have correlation with moon and tides but large forces involved with high-magnitude quakes far outweigh anything that can affect them."
Niwa programme leader for hazard and risk Rob Bell was the third person to quash the connection, as the perigean tides happened all around the world.
"To pick a location where it might stress a quake is just too hard to make,' he said.
Animals and their "sixth sense" also proved an unreliable predictor.
Ros Rowe of the Leg Up Trust said her horses "definitely" sensed the natural disaster, because she woke to a heavy, anxious whinny.
"That was just moments before the quake hit. They all sounded very unsettled and as it started I went outside and they ran to me. It was like they were seeking comfort from me."
Aubernee Kennels owner Faye Anderson said one dog may have sensed the quake because she heard a few "woofs" but other than that it was pretty tame.
"On the whole the dogs did not seem to worry, maybe they are used to quakes after living in an area that gets them regularly."
Gay Kingston, who lives at Ranui Farm Park, said no one in their household woke to animals making a racket.
"We have all sorts of animals from cows, donkeys and sheep and no one heard anything. There seemed to be nothing out of the ordinary."