Lithosphere-Asthenosphere boundary a thermal control of oceanic-lithosphere thickness. The continental lithosphere contains an ancient, stable part known as the craton. The LAB is particularly difficult to study in these regions and evidence suggests that the lithosphere within this old part of the continent is at it thickest and even appears to exhibit large variations in thickness beneath the cratons, thus supporting the theory that lithosphere thickness and LAB depth are age-dependent. Depths of the LAB beneath these regions (also known as shields and platforms) are estimated to be between 200 and 250 km deep. Beneath Phanerozoic continental crust, the LAB is roughly
What on Earth! Pindal in December 1963, with the working title "Automation", with the intention of showing how "in spite of appearances, man is the master in the automated world." The working title would become "Martians", before the final title "What on Earth!" was chosen. Drew was brought in to work on the film in 1965 and 1966, with Brittain assigned to write narration. Pindal's original idea of "man as the master" is not reflected in the final version of the film, and NFB archivist and blogger Albert Ohayon believes Brittain may have been responsible for this key change. "What on Earth!" was