Two days late and you know how that goes. But since today is the official anniversary of the most gigantic, earth shattering (practically) natural eruption ever: Krakatau aka Krakatao volcano in 1883, what film could possibly be more appropriate? MIGHTY MOUSE IN KRAKATOA, released in 1945 and directed by Connie Rasinski for Terry Toons.
The History channel has all the info on Mother Nature's most volatile eruption. A volcanic event which was felt around the world. In fact, it would surprise me if we weren't all still breathing Krakatau dust.