This is a visually stimulating look at volcano formation and their destructive capabilities, that would be great for an intro to volcanoes or igneous activity.
This is a short informational video on earthquakes and how they work that would be perfect for an after lecture break before entering into the lab or working on assignments..
This video would be a good tool to use to show students how the idea of Continental Drift could lead to Plate tectonics and shows the evidence behind the theory. Use of this video at the start of a plate tectonics unit would show some of the crucial evidence that led to the theory of Plate tectonics.
This Tour of the Cryosphere gives a brief, but nice overview of the elements that make up the Cryosphere that would be perfect as an intro to the topic or a post lecture video to break up the lecture and the activities of a lesson.