Convection Currents Ch. 1.2 pages 14-17 and Drifting Continents Ch. 1.3 pages 18-22 A. Heat transfer •  movement of energy from a warmer object to a cooler object. Ex: touch hot plate accidentally-heat moves Ex: ice cube in your hands, heat in hand moves to ice cube, causing your hand to become cold Three Types: 1. Radiation 2. Conduction 3. Convection 1. Radiation The transfer of energy through empty space. fire sun Radiation video 2. Conduction Heat transfer by direct contact of particles of matter. Conduction video 3. Convection •  Heat transfer by the movement of a heated fluid •  Caused by differences in temperature and density •  Heated particles spread apart-less dense •  Cool particles stay together-more dense Convection video B. Convection Currents in Earth’s Mantle The heating and cooling of the mantle, changes the magma’s density, and the force of gravity combine to sets the convection currents in motion. Ocean currents Convection Animation C. Alfred Wegener First, German scientist Second, 1910 proposed continental drift theory 1)Once “all lands” joined together and now drifted apart 2)Called “Pangaea” Third, To prove it, studied fossils, landmasses, climate http://www.ucmp.berkeley.edu/geology/anim1.html D. Evidence of Landforms •  Mountain ranges – similar rock patterns found in Argentina and South Africa. E. Evidence of Fossils •  Glossopteris and other fossils – found same patterns in South America and Africa. F. Evidence of Climate •  Tropical plants – found in cold climates G. Why did scientists reject Wegener’s Theory? •  Wegener could not provide a satisfactory explanation for the force that pushes or pulls the continents.