4 Geography · 4.1.2 Interior of the Earth and plate tectonics
4.1.2.4 Sea-floor spreading and palaeomagnetism
Harry Hess proposed in the early 1960s that new ocean floor forms at mid-oceanic ridges and is consumed at trenches; the matching magnetic stripes on both sides of the ridges, recorded as the Earth's field reversed, proved it and supplied the mechanism Wegener lacked.
- APPSC Group 1
- Advanced level
- 7 min read
- Full course
Key terms
- Harry Hess
- sea-floor spreading
- mid-oceanic ridge
- oceanic trench
- palaeomagnetism
- magnetic reversal
- normal polarity
- Vine-Matthews
- abyssal plain
- continental margin
- convection currents
- Arthur Holmes
What this note covers
- Core factsFoundation
- ExplainedStandard
- DeeperAdvanced
- Mains writingMains writing
- Common trapsFoundation
- Quick revisionFoundation
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