• Source: Lehmann discontinuity

The Lehmann discontinuity is an abrupt increase of P-wave and S-wave velocities at the depth of 220 km (140 mi) in Earth's mantle, discovered by seismologist Inge Lehmann. The thickness is 220 km . 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 asthenosphere, a phase transition, and most plausibly, depth variation in the shear wave anisotropy.




Notes






General references


P. Caloi (1967). "The "20° Discontinuity"". In H. E. Landsberg, J. Van Mieghem (ed.). Advances in geophysics, Volume 12. Academic Press. p. 167 ff. ISBN 0-12-018812-0. – some historic background.




Further reading


Shun-ichirō Karato (2008). Deformation of earth materials: an introduction to the rheology of solid earth. Cambridge University Press. p. 318. ISBN 978-0-521-84404-8.




External links


Inge Lehmann, UCLA
Career highlights of Inge Lehmann from UCLA

Kata Kunci Pencarian:

• Lehmann discontinuity
• Inge Lehmann
• Upper mantle
• Mohorovičić discontinuity
• Earth's inner core
• Mantle (geology)
• Internal structure of Earth
• Lehmann
• Darling in the Franxx
• Regression discontinuity design