Videos have emerged that appear to show the New Zealand sky lighting up in a range of colours as a magnitude-7.5 earthquake struck near Christchurch on Sunday night.
Footage uploaded to YouTube shows flashes of light in the sky which the uploader claims occurred “during the peak” of the quake.
A number of people commenting on the video from across New Zealand also claim to have witnessed the lights, which uploader Zachary Bell said lasted around “five to eight seconds”.
“The lights happened right on the peak of the shaking … [and were] of colours mainly green and blue and white, but a bit of yellow and other colour was there too [sic],” he said.
Reports of lights occurring during earthquakes date back thousands of years, with similar accounts also emerging after the Christchurch earthquake in 2011.
A paper published in science journal Seismological Research Letters hypothesised that the phenomena is a result of positive charge generated along stress gradients that “accumulate at the surface”.
High-density accumulations of charged atoms are thought to ionise pockets of air which form light-emitting plasma.
Lights believed to occur days, weeks before quake
Australian scientist Karl Kruszelnicki said the earthquake lights were a genuine phenomenon, however, there is no scientific consensus on the cause at this point.
A number of commenters on the video suggested the lights were caused by lightning or electrical transformers blowing up.
One commenter claiming to be a meteorologist and tornado scientist said he had observed similar effects in the United States when tornados hit power lines.
A video posted by Syrian Kiwi 💗 (@sana_aljoj) on
However, Mr Bell said the location of the lights over the ocean ruled out the power line theory.
Similar lights were filmed over China 30 minutes before the Sichuan quake in 2008.
According to the paper in Seismological Research, the lights have previously been observed weeks before an earthquake has struck. It is believed this is possible due to stress building in the fault zone during this period.