3Who? What? Where? When? Alfred Wegener Theory of Continental Drift German scientist who developed the Theory of Continental Drift in 1912The theory that states that the continents once formed a single landmass, broke up, and drifted to their present locations.
8Restless Continents Sea-Floor spreading The process by which new oceanic lithosphere forms as magma rises toward the surface and solidifiesOccurs at mid-ocean ridges (underwater mountain chains)CRT Question
9Restless Continents Magnetic Reversals Proof of Sea-floor Spreading Magnetic North and South poles switch positionsRecorded when molten rock solidifies
10Restless ContinentsSummary: Alfred Wegener developed continental drift hypothesis explaining that continents once formed Pangaea and then moved to their current positions. This occurs due to sea-floor spreading and that is proved by records of magnetic reversals solidified in new ocean rock.
11Objective: 5 October 2012Describe the theory of continental drift.OutroIf Sea-Floor Spreading continues, what will the Earth look like in another 250 MY? Describe it or draw a picture!
12Restless ContinentsWhen scientists proposed the Theory of Continental Drift, there were many skeptics. Which discovery confirmed that the continents move on plates?Deep-sea currentsEarthquake formationSpreading of the sea floorSedimentary rocksInterim 2