Lithosphere-Asthenosphere boundary Lithosphere-Asthenosphere boundary The Lithosphere-Asthenosphere boundary (LAB) represents a mechanical difference between layers in Earth’s inner structure. Earth’s inner structure can be described both chemically (crust, mantle, core) and mechanically. The Lithosphere-Asthenosphere boundary (referred to as the LAB by geophysicists) lies between Earth's cooler, rigid lithosphere and the warmer, ductile asthenosphere. The actual depth of the boundary is still a topic of debate and study, although it is known to vary according to the environment. The LAB is determined from the differences in the lithosphere and asthenosphere including, but not limited to, differences in grain size, chemical composition, thermal properties, and
Names for the human species "Gaian") is frequently used, as it were naming humanity by its planet of origin. Incidentally, this situation parallels the naming motive of ancient terms for humanity, including "human" ("homo", "humanus") itself, derived from a word for "earth" to contrast humans as earth-bound with celestial beings (i.e. deities) in mythology. Names for the human species The common name of the human species in English is historically "man" (from Germanic), often replaced by the Latinate "human" (since the 16th century). In addition to the generally accepted taxonomic name "Homo sapiens" (Latin: "sapient man", Linnaeus 1758), other Latin-based names for the human species