Earthquake light

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Seismic lights or earthquake lights are rare, mostly bluish, but sometimes also infrared light phenomena that occur before, during and occasionally after earthquakes . Such phenomena were already described in antiquity by Aristotle in his work Meteorologica and by the Roman writer Seneca . They are not limited to the immediate vicinity of the epicenter , but can also be observed hundreds of kilometers away. The existence of the phenomenon has long been considered controversial.

Observations

Selection of earthquakes these lights have been observed on, in chronological order:

exploration

There are various attempts to explain the cause of the earthquake lights. At the end of the 1990s it was discussed whether piezoelectric charges in the quartz components of the rock layers near the earth's surface, which are caused by the high pressure of tectonic movements, could trigger corresponding electrical discharges.

Another attempt at an explanation is aimed at local irregularities in the magnetic field of the earth or in the ionosphere , which then might as Rekombinationsleuchten or as erdoberflächennahe Aurora could be visible.

In January 2014, researchers from the Quebec Ministry of Natural Resources discovered a pattern behind the observations: 95% of global seismic activity occurs along the boundaries between two tectonic plates . However, 85% of earthquakes with earthquake lights are among the remaining 5% that occur within tectonic plates. It has also been shown in the laboratory that negatively charged oxygen ions , which can be released from the peroxides in certain types of rock by high pressure , generate a glowing plasma .

Furthermore, radon escaping from the earth's crust could strongly ionize the atmosphere days before an earthquake.

Near the coast, sonoluminescence in seawater is also discussed as a cause.

At the annual meeting of the European Geoscientific Union (EGU) in Vienna in 2015, scientists led by Eric Ferré from the Southern Illinois University (USA) presented research results, according to which pseudotachylites with a uniform orientation of iron-containing particles were found through drilling enormous current flow deep underground. According to the theory of the scientists, an earthquake creates such a high pressure along the collision zone of the rocks that the structures of the minerals are destroyed. This creates an electrical voltage, so that electricity flows through the minerals as a result. The voltage can discharge on the earth's surface, so that lightning or the luminous phenomena described so far can occur, like in a thunderstorm.

See also

Web links

Individual evidence

  1. ↑ a b c d e f g Gerald Traufetter: Lightning from the ground. In: SPIEGEL ONLINE. SPIEGEL ONLINE GmbH, October 13, 2003, accessed on September 1, 2014 .
  2. ↑ a b Earthquake Lights. In: Wissen.de. Konradin Medien GmbH, accessed on September 1, 2014 .
  3. ↑ Roland Knauer: A glow announces earthquakes. Electrical phenomena in the ground can be a sign of tremors. In: The world. WeltN24 GmbH, September 12, 2003, accessed on September 12, 2010 .
  4. ↑ Aristotle : Meteorology - Book II - Part 8 , 350 BC, translated by EW Webster, accessed September 20, 2017
  5. ↑ a b Walter Willems: Mysterious lights herald some earthquakes. Lights sometimes announce earthquakes weeks in advance and hundreds of kilometers away. Eyewitnesses report lightning bolts rising from the ground. Researchers are now trying to explain the phenomenon. In: The world. WeltN24 GmbH, January 6, 2014, accessed on June 9, 2015 .
  6. ↑ Bizarre Earthquake Lights Finally Explained
  7. ^ Hutton (1888). "The Earthquake in the Aimuri" . Transactions and Proceedings of the Royal Society of New Zealand 1868-1961  21 : 269-353.
  8. ^ Lane, FW: The Elements Rage (David & Charles 1966), pp. 175-6
  9. ↑ November 29, 1975 Kalapana Earthquake
  10. ↑ Tangshan: The Deadliest Earthquake
  11. ↑ 1976 Worst modern earthquake
  12. ↑ CHINA - Tangshan Earthquake of July 28,1976
  13. ↑ Light in the Sky (Luz) during Earthquake in Lima - Peru
  14. ^ Glowing lights around an earthquake's epicenter
  15. ^ Fidani, C. (2010). "The earthquake lights (EQL) of the 6 April 2009 Aquila earthquake, in Central Italy". Natural Hazards and Earth System Science  10  (5): 967-78. doi: 10.5194 / nhess-10-967-2010
  16. ↑ Fidani, C .: Statistical and spectral properties of the L'Aquila EQL in 2009 ( Memento from May 19, 2015 in the Internet Archive ). Bollettino di Geofisica Teorica ed Applicata, March 2012 (English)
  17. ↑ Some Bay Area Residents Report Mysterious Flashes In The Sky During Napa Quake
  18. ↑ Earthquake lights Santa Rosa / Napa Earthquake, Aug 24, 2014, 3:12 a.m. youtube.com, video (1:11 am), published Aug 27, 2014, last accessed October 27, 2015
  19. ↑ Light Show during Mexico's 8.4 quake
  20. ↑ Shunji Takaki, Motoji Ikeya: A Dark Discharge Model of Earthquake Lightning . In: Japanese Journal of Applied Physics . 37, 1998, pp. 5016-20. doi : 10.1143 / JJAP.37.5016 .
  21. ↑ Restless Earth - May Give Advance Notice of Large Earthquakes , NASA press release , December 7, 2001, accessed August 31, 2014
  22. ^ R. Theriault, F. St-Laurent, FT Freund, JS Derr: Prevalence of Earthquake Lights Associated with Rift Environments. In: Seismological Research Letters. 85, 2014, p. 159, doi: 10.1785 / 0220130059 .
  23. ^ Brian Clark Howard: Bizarre Earthquake Lights Finally Explained. Rare lights seen near earthquakes had long been called UFOs. National Geographic Society, accessed June 8, 2015 .
  24. ↑ Atmosphere Above Japan Heated Rapidly Before M9 Earthquake
  25. ^ Atmosphere-Ionosphere Response to the M9 Tohoku Earthquake Revealed by Joined Satellite and Ground Observations. Preliminary results. arxiv : 1105.2841
  26. ↑ a b c d Axel Bojanowski : Lightning from the ground: Geologists discover the origin of the earthquake lights. In: SPIEGEL ONLINE. SPIEGEL ONLINE GmbH, June 8, 2015, accessed June 8, 2015 .