1. A GIS Lesson

2. Only a hundred years ago, scientists thought that they understood the history of the Earth and how it got to be the way it is. But they still had a few questions ? ? ? ? ?

3. Why are most of the continents above the equator? Why is the Pacific Ocean so large? ? ?

4. Why are mountains in long ranges?

5. and why are there long chains of volcanoes?

6. Alfred Wegener proposed an idea in the early 1900’s He said that all the continents used to be together in one big chunk!

7. And then, somehow... …they moved like this

9. By the mid 1900’s scientist had collected lots of data but still had a hard time believing the continents were on big chunks!

10. We have the data… But is there any easier way to analyze it today?

11. To visualize the data we will use GIS software called ArcView.

12. With GIS you can combine layers of information about a place to give you a better understanding of that place

13. Use your cursor and double click on the ArcView GIS icon… Lets start investigating the theory of Plate Tectonics.

14. Credits Graphics used in this lesson were created using ArcView and ArcIms GIS software. Pictures are courtesy of USGS.