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 What on Earth What on Earth is a Canadian television panel game show and discussion program which aired on CBC Television from 1971 to 1975. It was based on the 1959 CBC game show "Who Knows?" The series featured items from the Royal Ontario Museum, the Ontario Science Centre and other facilities. These were brought before a panel who attempted to identify the objects. After the object's identity was guessed or revealed, it was the subject of further conversation by participants. This half-hour series was broadcast as follows (times in Eastern): Episodes were rebroadcast from July to September 1971, in