The Collaborative International Dictionary
Transition zone \Tran*si"tion zone\ (Biogeography) The zone lying between the Boreal and Sonoran zones of North America. It includes an eastern or humid subdivision and a western arid one of corresponding temperature comprising the northern Great Plains and the lower slopes of the mountains of the western United States and Mexico. Called also Neutral zone.
Wiktionary
n. 1 Any of several physical zones in which the properties, or the behaviour of something undergoes a radical change 2 # (context physics English) The stage in the flow or a fluid during which it changes from laminar to turbulent 3 # (context geology English) The region between the upper and lower mantle characterized by a rapid increase in density 4 # The area between a central business district and residential housing in a city
Wikipedia
The transition zone is part of the Earth’s mantle, and is located between the lower mantle and the upper mantle, between a depth of 410 and 660 km (250 to 400 miles). The Earth’s mantle, including the transition zone, consists primarily of peridotite, an ultramafic igneous rock.
The mantle was divided into the upper mantle, transition zone, and lower mantle as a result of sudden seismic-velocity discontinuities at depths of 410 and 660 km (250 to 400 miles). This is thought to occur as a result of rearrangement of atoms in olivine (which constitutes a large portion of peridotite) at a depth of 410 km, to form a denser crystal structure as a result of the increase in pressure with increasing depth. Below a depth of 660 km, evidence suggests that atoms rearrange yet again to form an even denser crystal structure. This can be seen using body waves from earthquakes, which are converted, reflected or refracted at the boundary, and predicted from mineral physics, as the phase changes are temperature and density-dependent and hence depth dependent.
Transition zone may refer to:
- Transition zone (Earth), a part of the Earth’s mantle located between the lower mantle and the upper mantle
- Transition zone, the region between the near and far fields of a transmitting antenna
- Transition zone (TZ), a glandular region of the prostate see Prostate#Zones
- Zone of transition, a zone in urban planning
- Transition zone, a part of the ocean between the bottom of the surface layer and deeper zones
Usage examples of "transition zone".
He shouted as he hit the transition zone, and again there was the rush of displaced air.
Lin wondered if his obsession with the transition zone reflected his form, or if his obsession came first.
When Bey headed for the transition zone, the other man trailed along behind.
Beyond the transition zone, the rails were laid with short gaps between ends.
From 400 to 650 km (250 to 400 mi) is a transition zone between the upper and lower mantle.
I didn't bring us out through the transition zone to our own universe.
But that's a long way off, and we poor souls are going to have to endure life in the transition zone during the foreseeable future.
There's a whole ecosystem dependent on the transition zone between inside and outside.
This is the transition zone that Simons was the first to enter and Gagarin the first to observe from above.
Beyond that point, however, there was not even any transition zone where one might have expected the less pretentious plant forms to taper upwards into the rocky desolation of the heights.
Above this 'transition zone' the main rocks are olivine, pyroxine, and garnet.