Global Volcanism Program | Image GVP-11290
Pyroclastic surge, or base surge deposits from the 1957 phreatomagmatic Capelinhos eruption lap up against a lighthouse near the western coast of Fayal Island in the Azores. Pyroclastic surges produced by magma-water interaction during the Surtseyan eruption nearly buried the lower floor of the lighthouse building. The initially submarine eruption began off the western tip of Fayal, forming a small island that was eventually joined to the main island.
Photo by R.V. Fisher, 1979 (University of California Santa Barbara).