For mystery, controversy and epic scale, nothing beats earthquake
lights – the unexplained illuminations in the sky that can accompany a
seismic shudder. For mystery, controversy and epic scale, nothing beats earthquake lights – the unexplained illuminations in the sky that can accompany a seismic shudder. The various theories include heat caused by friction, radon gas and piezoelectricity – an electric charge accumulating in quartz rocks as tectonic plates move
The mystery: what causes them? The controversy: do they even exist? And the epic status? Well, it’s like an earthquake and a lightning storm all rolled into one. It’s beyond Biblical.
The original article appears in issue 2 of the brand new science magazine, Science Uncovered, on sale now
Italian physicist Cristiano Ferugia assembled a complete account of earthquake
light reports dating back to 2000BC. For a long time, however,
geoscientists remained sceptical about the strange phenomenon. It wasn’t
until 1966 that hard evidence
emerged, in the form of photos from the Matsushiro earthquake in Japan.
Now, of course, you have only to head to the internet to come across
hundreds of pages full of earthquake light photos, many of dubious
authenticity.
But the lights appear in so many different colours and forms – from red
to white to blue, and in globes, flickers and glows – that it’s
difficult to spot a fake. The various theories include heat caused by friction, radon gas and piezoelectricity – an electric charge
accumulating in quartz rocks as tectonic plates move. In 2003, NASA
physicist Dr Friedemann Freund carried out lab experiments, which
suggested that earthquake lights are caused by electrical activity
in rocks. He said shockwaves from earthquakes can change the electrical
properties of silicon and oxygen-containing minerals, allowing them to
transmit currents and emit light.
But Professor David Brumbaugh, at the Arizona Earthquake Information Center
in Flagstaff, Arizona, thinks the theory can be considered only a
‘possible explanation’ at best. ‘Although Freund’s theory seems
promising, the answer may be a bit more complicated,’ he said.
Brumbaugh, however, admits he’s not aware of any new research that would
be as useful as Freund’s.
No comments:
Post a Comment