Pyroclastic density currents

Pete Rowley of the blog lithics has a great post about research he’s done on young pyroclastic density current deposits on Mount Ngauruhoe in New Zealand, a volcano used as a ‘stand in’ for Mount Doom in the Lord of the Rings series. Go read it, he’s got some great photos of the deposits and how they change along the profile.

Pete also links to this video of pyroclastic density currents in action on Mount Merapi in Indonesia. This footage shows numerous relatively small flows begin and then die out on the flank of the volcano. Also note the large boulders rolling down the mountainside and outrunning the flows.