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The magnitude-7.8 earthquake that rattle New Zealand early Monday morning local time ( Sunday sunrise EST ) , kill at least two people and stranding many others in the region , also had a foreign side effect : eerie blue and greenish flashes of luminosity in the sky during the trembling .
Only in late years have seismologists taken reports of these so - calledearthquake lightsseriously . It turns out that researchers still do n’t amply infer the phenomenon , but they do have a few clues about where and why it come about .
Near the epicenter of the 7.8-magnitude earthquake in New Zealand, a train track and state highway can be seen destroyed by landslide slips.
The strange light display — which may appear as sizzling flames emanate from the earth , flashes of lightning , ghostly earth or blue and green shimmer — usually occur at break where huge chunks of Earth are pulling off from each other , according to a 2014 study published in the journal Seismological Research Letters . [ Elves , Sprites & Blue Jets : Earth ’s Weirdest Lightning ]
Also in 2014 , researchers showed that shift grains surrounding a fault may beget an electrical billing , though exactly why this happens is badly understood .
Unexplained phenomenon
Observers have documented shimmering temblor lights more than 60 times over the past several centuries . In 2009 , for instance , before a major quake chance upon L’Aquila , Italy , bystanders account what search like flames sizzling from the sidewalk , and in Canada ’s Yukon Territory in the seventies , ghostly unripe orbs that were floating in the sky were ab initio thought to beUFOsbut were later determined to be tied to a nearby quake . But until recently , many researchers discounted these news report as hearsay .
" Earthquake lights are totally underreported , " Friedemann Freund , a crystallographer ( someone who studies the nuclear structure of material ) atNASA ’s Ames Research Center in Mountain View , California , and San Jose State University , antecedently told Live Science . " They are often things that occur within a fraction of a instant . "
But with the widespread accessibility of smartphones , these strange events are now being documented more oft .
In 2014 , Freund and his colleagues demo that 97 percentage of earthquake lights document since the 1600s occurred at defect that were withincontinental plates , rather than atsubduction zone , where one plate is diving beneath another . They found that 85 percentage of the incident occur where Earth buckle and produce a steep ravine or drop curtain in the Earth . This crevice allows magmatic rock and roll that originate thick belowground to bit by bit transmigrate up toward the surface , where they discharge vigor . Because of how the atoms in these rock are prepare , they may generate an electric charge more easily , flow upward to the airfoil , ionize the airwave and generate the light show , the research worker speculated .
In this scenario , earthquake lights may not even be wed to earthquakes . Changes in strain at a demerit can occur either due to a catastrophic rupture or because of a slow press release over days , and both forms could generate an electrical charge that ionize the air , consort to the enquiry .
“Crackpot physics”
In a freestanding work detail at the 2014 American Physical Society meeting in Denver , researchers filled Tupperware container with mixtures of plastic discs , chicken feed particle and powders , such as flour , and watched what happened as they stuck and slipped past one another . These mixtures were meant to mime the way texture of Earth move in an seism zone .
The researchers obtain thatthe mixture reliably generated high potential drop when tipped , even though they could not explain why .
" Except for the fact that we can not get these voltages to go away , I would call this ' crackpot purgative , ' " Troy Shinbrot , an hold physicist at Rutgers University in New Jersey , antecedently assure Live Science . " And even as it is — I wish I could hedge my bet , but the potential are very quotable , and we have so far failed to calculate for a inauthentic influence that might cause them . "
Original article onLive Science .
