Petrichor

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Petrichor (/ˈpɛtrɨkɔər/) is the scent of rain on dry earth, or the scent of dust after rain. The word is constructed from Greek, petros, meaning ‘stone’ + ichor, the fluid that flows in the veins of the gods in Greek mythology. It is defined as "the distinctive scent which accompanies the first rain after a long warm dry spell".[1]

The term was coined in 1964 by two Australian researchers, Bear and Thomas, for an article in the journal Nature.[2][3] In the article, the authors describe how the smell derives from an oil exuded by certain plants during dry periods, whereupon it is absorbed by clay-based soils and rocks. During rain, the oil is released into the air along with another compound, geosmin, a metabolic by-product of certain Actinobacteria, which is emitted by wet soil, producing the distinctive scent; ozone may also be present if there is lightning.[4] In a follow-up paper, Bear and Thomas (1965) showed that the oil retards seed germination and early plant growth.[5] This would indicate that the plants exude the oil in order to safeguard the seeds from germination under duress.

References[edit]

  1. ^ Wiktionary
  2. ^ Bear, I.J.; R.G. Thomas (March 1964). "Nature of argillaceous odour". Nature 201 (4923): 993–995. doi:10.1038/201993a0. 
  3. ^ Garg, Anu (2007). The Dord, the Diglot, and an Avocado Or Two: The Hidden Lives and Strange Origins of Words. Penguin. p. 399. ISBN 9780452288614{{inconsistent citations}} .
  4. ^ Daisy Yuhas (July 18, 2012). "Storm Scents: It's True, You Can Smell Oncoming Summer Rain: Researchers have teased out the aromas associated with a rainstorm and deciphered the olfactory messages they convey". Scientific American. Retrieved July 20, 2012. 
  5. ^ Bear, I.J.; R.G. Thomas (September 1965). "Petrichor and plant growth". Nature 207 (5005): 1415–1416. doi:10.1038/2071415a0. 

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