The largest supermoon in seventy years has been people questioning whether there’s any connection to this morning’s earthquake. Join Tristram Clayton as he learns more from University of Melbourne Associate Professor of active tectonics, Mark Quigley.
Scientists have debunked a post, which warned a 'major earthquake' would hit the South Pacific on November 14 because of the supermoon, after it gained prominence this morning.
The post was circulating on various social media outlets today in the wake of the 7.5 magnitude earthquake which struck the South Island early this morning, killing two.
The warning, posted by Nigel Antony Gray on November 6, urged people to stock up on supplies and be prepared in case an earthquake struck the region in coming days.
However, earthquake experts have rubbished his theories, saying there is no evidence linking supermoons with earthquakes, and no science to predict when an earthquake will occur.
"Heads Up: On 14th November and a couple of days either side of that date, watch for a major earthquake, and quite possible in South Pacific area," Gray's warning begins.
"The reason for this is that 14th of Nov will be a 'supermoon' largest for this century."
That meant there would be increased gravitational pull from the moon, he said, and combined with the recent large earthquakes in Italy, could cause stress on tectonic plates in other areas.
"[T]he chances of a big quake are higher for something down this end of the globe," he said.
He tempered his warning, saying it was "just a possibility", but urged people to be alert and always prepared with essential water and food supplies.
Gray was last night posting about the magnitude 7.5 earthquake in Hanmer Springs.
Screenshots of his prediction have been posted numerous times on Twitter, and his name was this morning appearing as a trending search topic on Facebook.
Two people have died and there are reports of other casualties following the quake, which struck at 12.02am.
However, GNS Science seismologist Dr John Ristau said there was no evidence linking supermoons to earthquakes.
"There's no direct link between them," he said.
An earthquake such as the one which struck the South Island this morning would occur in the south Pacific around once a year, Ristau said.
"In this part of the world, If you think of New Zealand, going all the way up to Samoa and Fiji and off to the Solomon Islands and Vanuatu and all these places, and even including the Philippines in the south Pacific, a 7.8 [magnitude earthquake] you could probably find one at least every year that happens somewhere in the region.
"So it's really just a coincidence that it happened at the same time as the moon."
A recent paper by some Japanese researchers found a weak correlation between high tides at full moon and earthquakes, he said.
"But basically what they found is that if you have a fault that is really close to the tipping point, a fault that's almost about to break, that given enough time - probably a very short amount of time - would rupture in a major earthquake anyway, it just might happen because the tides can put some stress on the crust."
For these "really shallow earthquakes" the high tide "could be just - just - enough to be the straw that broke the camel's back", Ristau said.
"But it could also be just as likely that nothing happens and then two weeks later just through normal tectonic forces it finally loads up enough stress and that ruptures the fault too."
Ristau also poured cold water on the link to the recent earthquakes in Italy, saying: "It's a real stretch to say that the earthquakes in Italy are having any real effect on what's happening in the south west Pacific."
The earthquakes in Italy, also destructive and deadly, had been relatively small in comparison to a severe quake, he said, but had caused a lot of damage because they occurred in highly populated areas.
His analysis was supported by other experts, who said such predictions were not supported by scientific evidence, and advised people to ignore them.
Victoria University earthquake scientist Associate Professor John Townend said there was no way of forecasting earthquakes with any degree of reliability.
The message people should be taking on board was to be prepared at all times, Townend said.
GeoNet also cautioned people against unscientific theories.
"We understand that a supermoon is going to happen tomorrow night," GeoNet stated today.
"However, we only report on information and correlations that can be verified through our instruments and backed up by our friends at the USGS [United States Geological Survey]."
