History of Plate Tectonics

1. History of Plate Tectonics

2. 1490 – Leonardo Da Vinci • Noticed on early charts that the continents would fit together like a jigsaw puzzle

3. 1620 - Francis Bacon • Also noticed the “fit” of the continents

4. 1885 – Edward Suess • Thought that there was once a single large land mass. Source: www.usgs.gov

5. 1912 – Alfred Wegener • German meteorologist and polar explorer • Proposed the continental drift theory • He suggested that all earth’s land had once been joined into a single supercontinent called Pangaea. • Wegener thought Pangaea had broken into pieces about 200 million years ago.

6. 1912-1934 • Most established geologists dismissed Wegener’s ideas.

7. 1935 – Kiyoo Wadati • Japanese Scientist • Speculated that earthquakes and volcanoes near Japan might be associated with continental drift

8. 1940 – Hugo Benioff • Plotted the locations of deep earthquakes at the edges of the Pacific ocean. • Pacific Ring of Fire: A circle of violent geological activity surrounding much of the Pacific Ocean. Found patterns of earthquakes and volcanoes

9. 1960 – Harry Hess & Robert Dietz • Harry Hess – Princeton • Robert Dietz – Scripps • Proposed seafloor spreading and the “fit” of the continents

10. 1965 – John Tuzo Wilson • Toronto • Ideas of continental drift and seafloor spreading were integrated into the overriding concept of plate tectonics. • In this theory, Earth’s outer layer consists of about a dozen separate major lithospheric plates floating on the asthenosphere.

11. Plate Movement • Plate movement is slow in human terms, averaging about 5 centimeters per year. • Plates interact at: • Convergent Boundaries • Divergent Boundaries • Transform Boundaries