Augustine Volcano

Augustine Volcano is a frequently active stratovolcano in southcentral Alaska that forms Augustine Island in southwestern Cook Inlet. Its summit and flanks were built by many historic and prehistoric eruptions, creating overlapping lava domes, ash and pyroclastic deposits, lahars, and large avalanche debris from repeated collapses of summit domes into the inlet. Those collapses shaped the island’s irregular shoreline and hummocky lower slopes. Major eruptions have been recorded from 1883 through 2006, with larger events typically beginning explosively and then shifting to lava effusion. Ash from the 1976 and 1986 eruptions reached Anchorage and disrupted air traffic, showing the volcano’s regional impact.

Pedro Bay, Alaska · United States