How Volcanoes Work

 Image Described in Caption Eruption of Capelinhos, Azores (1957) -- The hydrovolcanic (Surtseyan) eruption of Capelinhos occurred on the western extremity of Fayal Island in the Azores. The eruption generated a new island that coalesced with the mainland, thus adding an additional square mile to Fayal Island. The photo here captures a magnificent example of a base surge due to column collapse of the eruptive column. Courtesy of R. V. Fisher.