Augustine Volcano (Sugpiaq: Utakineq; Dena'ina: Chu Nula) is a lava dome volcano in Alaska consisting of a central complex of summit lava domes and flows surrounded by an apron of pyroclastic, lahar, avalanche, and ash deposits. The volcano is frequently active, with major eruptions recorded in 1883, 1935, 1963–64, 1976, 1986, and 2006. Minor eruptive events were reported in 1812, 1885, 1908, 1944, and 1971. The large eruptions are characterized by an explosive onset followed by the quieter effusion of lava. It forms Augustine Island in southwestern Cook Inlet in the Kenai Peninsula Borough of southcentral coastal Alaska, southwest of Anchorage. Augustine Island has a land area of , while West Island, just off Augustine's western shores, has . The irregular coastline of Augustine Island is due to the repeated catastrophic collapse of the summit dome, forming debris avalanches down the flanks and into Cook Inlet. The island is mainly made up of past eruption deposits. Scientists have been able to discern that past dome collapse has resulted in large avalanches. Description and geologic history The nearly circular uninhabited island formed by Augustine Volcano is wide east-west, north-south; a nearly symmetrical central summit peaks at altitude . Augustine's summit consists of several overlapping lava dome complexes formed during many historic and prehistoric eruptions. Most of the fragmental debris exposed along its slopes comprises angular blocks of dome-rock andesite, typically of cobble to boulder size but carrying clasts as large as 4 to 8 meters (10 to 25 feet), rarely as large as 30 meters (100 ft). The surface of such deposits is hummocky, a field of steep conical mounds and intervening depressions with many meters of local relief. En route to Katmai in 1913, Robert F. Griggs had briefly inferred landslide (debris avalanche) as the origin of Augustine's hummocky coastal topography about Burr Point, by geomorphic analogy with the hummocky and blocky deposit of a 1912 landslide near Katmai. The hummocky deposits on Augustine's lower flanks resemble both topographically and lithologically those of the great landslide or debris avalanche that initiated the spectacular May 18, 1980, eruption of Mount St. Helens. The deposit of that landslide revealed the origin of coarse diamicts with hummocky topography at other strato volcanic cones. Since 1980 many hummocky coarsely fragmental deposits on Augustine's lower flanks have come to be interpreted as deposits of numerous great landslides and debris avalanches. Eruptive activity January 22, 1976,