1. Evidence after wegener: distribution of earthquakes and volcanoes
2/17/16
Evidence after wegener: distribution of earthquakes and volcanoes
Objective: I will explain how the distribution of earthquakes and volcanoes around the world provide evidence for plate tectonics.
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2. Increase in Technology
Global seismic and volcanic data improved in the 60s and 70s
Establishment of the Worldwide Standardized Seismograph Network (WWSSN)

3. Finding a Pattern
When looking at global EQ and VOL data, scientists found a pattern
EQ and VOL were focused in clusters and bands

4. Finding a Pattern
The patterns aligned with mid-ocean ridges and trenches

5. Ring of Fire
The largest cluster formed lining the Pacific Ocean, known as the "Ring of Fire"

6. Evidence for Plate Tectonics
Scientists developed new ideas about Earth’s crust
Concluded that Earth was broken up into plates and the interactions at plate boundaries are responsible for many geologic processes.