Lehmann discontinuity


Lehmann discontinuity

The Lehmann discontinuity, named after seismologist Inge Lehmann, is the discontinuity in seismic velocity near a depth of 220 km, which is still debated. It appears beneath continents, but not usually beneath oceans, and does not readily appear in globally-averaged studies. Several explanations have been proposed; a lower limit to the pliable aesthenosphere, a phase change, and most plausibly, depth-variation in the shear wave anisotropy. The Lehmann discontinuity at one time referred to the inner core-outer core boundary, as Inge Lehmann discovered the inner core, but that usage is no longer current.

ee also

*Mohorovičić discontinuity
*Gutenberg Discontinuity

References

* [http://geology.about.com/library/weekly/aa031598.htm "From here to "hell," or the D" layer"] , About.com
* [http://www.physics.ucla.edu/~cwp/articles/bolt.html "Inge Lehmann"] , UCLA


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Lehmann — is a common Germanic surname derived from the German word Lehen , meaning fiefdom. Some Jewish Lehmann families state that the origin of their name is from the German words for Lion Man (i.e. from Yehuda the tribe of the lion). It may refer to: * …   Wikipedia

  • Lehmann , Inge — (1888–1993) Danish seismologist It was Lehmann who, in 1936, first put forward the view that the Earth s core consisted of two parts – an inner and an outer, separated by a discontinuity. For many years it had been thought that the Earth… …   Scientists

  • Inge Lehmann — (May 13, 1888 ndash; February 21, 1993), Fellow of the Royal Society of London, was a Danish seismologist who, in 1936, argued that the Earth s core is not one single molten sphere, but that an inner core exists which has physical properties that …   Wikipedia

  • Mohorovičić discontinuity — Earth cross section showing location of the Mohorovičić discontinuity …   Wikipedia

  • Discontinuite de Lehmann — Discontinuité de Lehmann Structure de la Terre. 1. croûte continentale, 2. croûte océanique, 3. manteau supérieur, 4. manteau inférieur, 5. noyau externe, 6. noyau interne, A : Discontinuité de Mohorovic, B: Discontinuité de Gutenberg, C:… …   Wikipédia en Français

  • Discontinuité De Lehmann — Structure de la Terre. 1. croûte continentale, 2. croûte océanique, 3. manteau supérieur, 4. manteau inférieur, 5. noyau externe, 6. noyau interne, A : Discontinuité de Mohorovic, B: Discontinuité de Gutenberg, C: Discontinuité de Lehmann La …   Wikipédia en Français

  • Discontinuité de lehmann — Structure de la Terre. 1. croûte continentale, 2. croûte océanique, 3. manteau supérieur, 4. manteau inférieur, 5. noyau externe, 6. noyau interne, A : Discontinuité de Mohorovic, B: Discontinuité de Gutenberg, C: Discontinuité de Lehmann La …   Wikipédia en Français

  • Discontinuité de Lehmann — Structure de la Terre. 1. croûte continentale, 2. croûte océanique, 3. manteau supérieur, 4. manteau inférieur, 5. noyau externe, 6. noyau interne, A : Discontinuité de Mohorovic, B: Discontinuité de Gutenberg, C: Discontinuité de Lehmann La …   Wikipédia en Français

  • Structure of the Earth — Earth cutaway from core to exosphere. Left picture is not to scale. The interior structure of the Earth, similar to the outer, is layered. These layers can be defined by either their chemical or their rheological properties. The Earth has an… …   Wikipedia

  • Mantle (geology) — For other uses, see Mantle (disambiguation). Earth cutaway from core to exosphere. The mantle is a part of a terrestrial planet or other rocky body large enough to have differentiation by density. The interior of the Earth, similar to the other… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.