Volcanoes

https://news.bbc.co.uk/2/hi/science/nature/7533964.stm

This website has an animated guide to how and where volcanoes form.   It has 12 mini animations that introduces the igneous processes  involved with volcano building, types of volcanoes, as well as key terminology.   They are tiny, but you could zoom it in to fill the screen.   I like the very simple diagrams, especially for introducing the vocabulary to my ELL kids.