GEOL 1001 Chapter : 32387a53d306c3797a84c57e37fb932b
Document Summary
In the past, it was shorter because earth rotation was faster: precession- wobble of earth on its axis- varies with age, recent rates-18-20 kyr. In the past, it was shorter because earth rotation was faster. If earth has no orbital eccentricity, it would orbit the sun equally. If it has eccentricity, it orbits close and far from the sun: plate tectonics causing ocean circulation changes- scotese movie. Pleistocene and pre-pleistocene glaciation: most recent maximum- 18000 years ago back to -2,000,000-cycles of glaciation (cold. The glacier is breaking off (calving) icebergs into icy bay, which is a fiord: ice sheets, broad glaciers of irregular shape. Ice cap- small ice sheet: continental ice sheet- great size, covers mountains, domelike, greenland- 3km thick in places, antarctic- >4km thick, 66% fresh water in the world, located over the south pole. Ice motion- upper surface yields crevasses: internal flow or creep- crystal deform, sliding along the ground or slipping- basal slip.
