ultralow-velocity zone

ultralow-velocity zone

[‚əl·trə·lō və′läs·əd·ē ‚zōn]
(geophysics)
Thin, mushy layer detected in some places along the earth's core-mantle boundary where seismic waves slow down.
References in periodicals archive ?
Those regions, dubbed ultralow-velocity zones, range between 5 and 40 km thick and can measure more than 100 km across.
In ultralow-velocity zones, seismic pressure waves slow 5 to 10 percent, sws Mao.
High iron concentrations could also explain the high density of minerals inferred from past observations of ultralow-velocity zones, he notes.