Lithosphere for silicate rocks, and formula_4 is the age of the given part of the lithosphere. The age is often equal to L/V, where L is the distance from the spreading centre of mid-oceanic ridge, and V is velocity of the lithospheric plate. Oceanic lithosphere is less dense than asthenosphere for a few tens of millions of years but after this becomes increasingly denser than asthenosphere. This is because the chemically differentiated oceanic crust is lighter than asthenosphere, but thermal contraction of the mantle lithosphere makes it more dense than the asthenosphere. The gravitational instability of mature oceanic lithosphere has the
Common name in English, including “stone curlews”, so the choice of the name “thick-knees” is not easy to defend but is a clear illustration of the hazards of the facile coinage of terminology. For collective nouns for various subjects see a list of collective nouns (e.g. a flock of sheep, pack of wolves) Some organizations have created official lists of common names, or guidelines for creating common names, hoping to standardize the use of common names. For example, the Australian Fish Names List or AFNS was compiled through a process involving work by taxonomic and seafood industry experts, drafted using the CAAB