Mohorovičić discontinuity
From Wikipedia, the free encyclopedia
The Mohorovičić discontinuity, usually referred to as the Moho, is the boundary between the Earth's crust and the mantle. The Moho serves to separate both oceanic crust and continental crust from underlying mantle. The Moho mostly lies entirely within the lithosphere; only beneath mid-ocean ridges does the Moho also define the lithosphere-asthenosphere boundary. The Mohorovičić discontinuity was first identified in 1909 by Andrija Mohorovičić, a Croatian seismologist, when he observed the abrupt increase in the velocity of earthquake waves (specifically P-waves) at this point. Ophiolites are sections of oceanic crust and possible mantle rock that have been obducted into the continental crust during plate collisions.
The Mohorovičić discontinuity is about 5 km below the ocean floor and 30 to 50 km beneath typical continents. The Moho is deepest beneath the Tibetan Plateau, where it is approximately 75 km below the surface.
During the late 1950s and early 1960s, there was a proposal taken up in the executive committee of the National Science Foundation to drill a hole through the ocean floor to reach this boundary. However the operation, named Project Mohole, never received sufficient support and the proposal was canceled by US Congress in 1967. This remains as an important scientific objective, which is being addressed by scientific drilling.
A more recent proposal considers a self-descending tungsten capsule heated by radiogenic heat to explore Earth’s interior near the Moho discontinuity and in the upper mantle.[1]
Contents |
[edit] Moho in popular culture
 |
This article does not cite any references or sources. (September 2007) Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. |
The Mohorovičić Discontinuity is mentioned in the Real-time strategy game Total Annihilation , in which you can build Moho Mines to supplement your Metal.
The Mohorovičić Discontinuity is also mentioned in the novel Abduction by Robin Cook, in which a team of scientists are abducted by inhabitants of an underground civilization.
In the cartoon Inhumanoids the monster, D-Compose's kingdom of Skellweb lies within the Moho.
In Star Control 2, one of the "ramblings" of the odd Mycon race refers to the Deep Children as "Dwellers in the Mohorovichic."
Deep Storm: A Novel by Lincoln Child details an expedition where a team of scientists attempts to drill through the ocean floor to the Mohorovičić Discontinuity.
In The Mohole Mystery by Hugh Walters, lethal microbes and belligerent egg-shaped creatures are found to inhabit the Mohorovičić Discontinuity when a manned rocket-propelled capsule is sent down to investigate.
In the Mars trilogy by Kim Stanley Robinson, the colonizers of Mars dig deep "moholes" to allow outgassing from the planet's interior as a means to increase the atmospheric pressure - thus contributing to the terraforming of the planet.
Also, in Sid Meier's Alpha Centauri game, the Mohorovičić Discontinuity is mentioned.
In the novel Bolo Stroke by Willian H. Keith, the Mohorovičić Discontinuity is mentioned in Chapter 21 when the Bolo Victor is contemplating the origins of the Aetryx.
In the popular 1999's FPS game Unreal Tournament the Mohorovičić Discontinuity is mentioned as a place of one of the battle arenas.
[edit] See also
- Gutenberg Discontinuity
- Lehmann discontinuity
- Brittle-ductile transition zone
- Kola Superdeep Borehole
[edit] References
- ^ M.I. Ojovan, F.G.F. Gibb, P.P. Poluektov, E.P. Emets. Probing of the interior layers of the Earth with self-sinking capsules. Atomic Energy, 99, No. 2, 556-562 (2005)
- Harris, P., 1972, 'The composition of the earth', in Gass, I.G., Smith, P.J., and Wilson, R.C.L. (eds), Understanding the Earth: A Reader in the Earth Sciences. The Open University Press.
- Schlumberger Oilfield Glossary
Douglas Dixon, P., 2000, "Beginners Guide To Geology" Chancellor Press.
