Earthquake light

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An earthquake light is an unusual luminous aerial phenomenon, similar in appearance to the aurora borealis, that allegedly appears in the sky at or near areas of tectonic stress, seismic activity or volcanic eruptions. Scientific evidence for the presence of lights is unreliable, given that there are few references documenting the phenomenon.

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[edit] Appearance

The lights are most evident in the middle period of an earthquake, although there are reports of lights that occurred after or quite often before the earthquake, such as before the 1976 Tangshan earthquake.[citation needed] They usually have shapes similar to those of the auroras with white to bluish hue, but occasionally they have been reported to have a wider color spectrum.[citation needed] The luminosity is typically visible for several seconds, but there have been cases in which they lasted tens of minutes. In the 1930 Idu earthquake, lights were reported up to 70 miles from the epicentre.[1], although most lights are not so far away.[citation needed]

There have also been cases in which electromagnetic waves caused by the earthquake interfered with radio transmissions, such as during the Great Chilean Earthquake of 1960.[citation needed]

Distinguishing earthquake lights from other transient optical phenomena can be difficult during the chaos of a tremor. For example, a bluish-white flashes that are accompanied by loud bangs or hissing during an earthquake are more likely the result of electrical arcing in power lines or transformers. However, in some videos, the light can be seen as a long flash in the night high in the sky[2].

[edit] History

Records of earthquakes that were accompanied by lights can be found as far back as 373 BC in ancient Greek writings, that "immense columns of flame" foretold the earthquake that destroyed the cities of Helike and Boura[citation needed]. However, even in the early 20th century they were still considered a myth, despite an investigation of lights seen during the 1930 Idu earthquake by researchers from Tokyo University,[3] until photographs of actual lights were taken in Japan in the 1960s.

The night before the 1976 Tangshan earthquake, many people in Tangshan reported seeing strange lights.[citation needed]

In Peru's earthquake that occurred south of Lima on August 15, 2007, earthquake lights could be seen across the Lima sky before and during the earthquake. Several videos were taken. [4]

On May 12, 2008, 30 minutes prior to the Sichuan Earthquake, a cell phone captured footage of multi-colored clouds in the sky[1]. The footage was uploaded to Youtube[5]. There is also footage from Meixian, Shaanxi,[6] approximately 550km northeast of the epicenter, recorded 10 minutes before the earthquake. However, the footage appears to show a circumhorizontal arc, which is caused by refraction of the sun's light through ice particles in a cirrus cloud, similar to a rainbow.[citation needed] Earthquake lights were also spotted in Tianshui, Gansu[7][8], approximately 400 km north-northeast of the epicenter.

[edit] Theories

The precise mechanism, if such a phenomenon exists—as opposed to being coincidence with aurora or mistaken recall after a traumatic event such as an earthquake—is unknown. One theory suggests that earthquake lights are a form of plasma discharge caused by the release of gases from within the Earth and are electrically charged in the air.[citation needed]

Another possible explanation is local disruption of the Earth's magnetic field and/or ionosphere in the region of tectonic stress, resulting in the observed glow effects either from ionospheric radiative recombination at lower altitudes and greater atmospheric pressure or as aurora. However, the effect is clearly not pronounced or notably observed at all earthquake events and is yet to be directly experimentally verified.[citation needed]

Another explanation involves intense electric fields created piezoelectrically by tectonic movements of rocks containing quartz[9].

Some similar clouds have been reported during nuclear tests [10] and Radon is likely to be an earthquake precursor[11], so another theory is that glowing clouds might be light emission produced by Nuclear reactions[citation needed] or ionization and plasma-chemical reactions[12]

If such a phenomenon exists, it will bring a new explanation to many cases of UFO sightings.

[edit] See also

[edit] References

  1. ^ Lane, F. W. The Elements Rage (David & Charles 1966), pp175-6
  2. ^ Earthlights on Peru’s Earthquake? Editor: Kentaro Mori, August 17th, 2007, forgetomori.com
  3. ^ Lane, F. W. The Elements Rage (David & Charles 1966), pp175-6
  4. ^ Earthquake Lights (EQLs)
  5. ^ Colorful clouds spotted in Tianshui, Gansu province, 30 minutes before the 2008 Sichuan earthquake
  6. ^ Colorful clouds spotted in Meixian, Shaanxi province, 10 mins before the 2008 Sichuan earthquake
  7. ^ "Buddha's Halo" appears at Nanguo Temple (Chinese). Tianshui Online (2008-05-12). Retrieved on 2008-05-20.
  8. ^ Paul Simons (2008-03-15). Glowing lights around an earthquake's epicentre. Times Online. Retrieved on 2008-05-20.
  9. ^ Takaki, Shunji and Ikeya, Motoji, A Dark Discharge Model of Earthquake Lightning, Japanese Journal of Applied Physics, Volume 37, Issue 9A, pp. 5016 (1998)
  10. ^ earthquake prediction-meteoquake
  11. ^ Richon P., Sabroux J.-C., Halbwachs M., Vandemeulebrouck J., Poussielgue N., Tabbagh J., Punongbayan R. (2003), Radon anomaly in the soil of Taal volcano, the Philippines: A likely precursor of the M 7.1 Mindoro earthquake (1994), Geophysical Research Letters, Volume 30, Issue 9, pp. 34-1
  12. ^ http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVS-4GXVGHW-3&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=162ef39f20e8a3e074333af1eddeea60

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