The footage clearly shows a ball of light pulsing for around eight seconds on the
horizon in Tokyo during the aftershock.
It registered 7.1 on the Richter scale and struck 40 miles east of Sendai along the
same fault line as last month's quake.
We take a look at several theories as to what could have caused the bizarre
phenomenon, from the plausible to the wacky, and get some insight from an
The most widely circulating explanation is that this was an 'earthquake light' -
literally a light that appears in the sky during times of seismic activity.
There have been a number of recorded instances of these - at Kalapana in 1975,
L'Aquilla in 2009 and Chile in 2010 - but the phenomenon is not universally
accepted in the scientific community.
Dr David Robinson, an earthquake researcher at Oxford University, told
Yahoo! News one reason why these might happen.
"The idea is that just before an earthquake, you might get some build up of stress
just prior to the event.
"People have invented all kinds of mechanisms whereby this stress gets released as
an electromagnetic excitation of the upper atmosphere, which can cause things like
lights appearing, similar to the Northern Lights."
The problem with this theory, said Dr Robinson, was that no-one has yet come up
with a plausible reason for why this actually happens. "Anything which is caused
by an unknown mechanism is dubious," he said.
A second issue is that while there have been several recorded instances of
'earthquake lights', they don't happen during every earthquake.
"There are satellites up there that record every thunderstorm that happens on
earth. If you're getting something similar to a flash of lightning during an
earthquake then they're going to measure it, but that's not happening."
There are a couple of other explanations that could explain this though. The
first concerns quartz. When tectonic plates containing the mineral rub against
each other, they create intense electric fields (called piezoelectricity). This could
manifest itself as flashes of light.
A second, tantalizing possibility is these lights could actually predict upcoming
quakes. This theory suggests that before a quake, the ground 'exhales' radon,
which results in light emissions in the atmosphere. Dr Robinson says this is
"clutching at straws" though.
He doesn't rule out earthquake lights, but feels the subject needs more study.
"Just because they can't be explained doesn't necessarily make them not true.
But until anyone comes up with a plausible mechanism it will be on the fringes
of earthquake study."
Another possible theory for the burst of light is that it was some kind of
electrical explosion. It's been speculated that the flash was an electrical
transformer exploding after being struck by the quake.
During Thursday'squake 3.6million homes in North East Japan area lost power,
traffic signals and road lights also stopped working. 900,000 houses were still
affected on Friday afternoon.
A spokesman for the Tohuku Electric Power Company said six power plants in the
area went down after the tremor and power lines throughout the area were
damaged, making this explanation a possibility.
A US 'superweapon'
We're into the outlandish territory now. Many commentators, including oddball
conspiracy theorist David Icke, have said the footage was evidence of 'Haarp'
(High Frequency Active Auroral Research Program).
Based in Alaska, this weather program was set up by the US Air Force, Navy and
University of Alaska to research the upper atmosphere (the ionosphere) with a view
to improving satellite communication.
Some have speculated that Haarp can physically change weather conditions, and
the project's been blamed for triggering floods, hurricanes, droughts, the earthquakes
in Haiti and Pakistan and even Gulf War Syndrome. Mind control is another one of
its supposed capabilities.
Suffice to say the events in Japan have also been attributed to this 'superweapon' -
with former governor of Minnesota and pro-wrestler Jesse Ventura telling Piers
"The US's HAARP weapon system can cause natural disasters, including
earthquakes and tsunamis like the one that happened in Japan."
Whenever grainy handheld footage of a glowing light in the sky surfaces, it's only a
matter of time before it's held up as evidence of UFOs. This video is no exception.
A quick YouTube search reveals a spate of alien sightings in the build up to the
Japan earthquake, with little green men spotted above Kyoto and the Sakurajima
Volcano. Even Chinese news agency Xinyua reported UFOs flying over Mount Fuji
An alien spacecraft was also spotted during recent Japanese news coverage of the
Earthquake, but this was later confirmed to be a helicopter.