How Volcanoes Work

 Image Described in Caption Pyroclastic flow, Mt. Pelée, Matrinique (1902) -- The village of St. Pierre on the island of Martinique was destroyed by a pyroclastic flow similar to the one shown here. This photo was taken a few months after the destruction of St. Pierre. Pyroclastic flows had not been previously described by volcanologists. This type of pyroclastic flow is called a nuée ardente, composed of hot, incandescent solid particles derived from the collapse of a lava dome. Other types of pyroclastic flows, derived from collapse of the eruptive column, are pumice bearing, and their deposits are called ignimbrites. Photo by Lacroix, 1902.