coulée

Lava flows from Kilauea in Hawai`i move towards a home in Kalapana. Whenever I think about the hazards posed by most lava flows, I tend to think about the opening scene in the Hitchhiker's Guide to the Galaxy. Developers are planning to knock our hero Arthur Dent's house down and as a last ditch effort to stop its destruction, Arthur lies down in front of the bulldozer. The demolition supervisor, a certain Mr. Prosser, at one point asks Arthur if he knows how much damage the bulldozer might suffer if he just lets it roll over poor Mr. Dent. Arthur says he doesn't know and Mr. Prosser replies…

As a volcanologist, I am partial to impressive lava flows, especially in volcanoes that erupt material that you'd think wouldn't produce big flows. For example, there are quite a few volcanoes in the Chilean Andes that erupt dacite lavas, which are relatively viscous (sticky), so you might expect it to erupt explosively. However, you can get large dacitic to rhyolitic lava flows, quite commonly, and these large flows are called coulées (a "volcanic dome flow"). Lllullaillaco volcano on the Chile/Argentina border. Note the very prominent coulée with flow levees. Click on the image to see a…