Augustine Volcano is a 1,250 metres (4,100 ft) high volcano in southwestern Cook Inlet, about 280 kilometres (170 mi) southwest of Anchorage, Alaska. More than half the people of Alaska live no more than about 300 kilometres (190 mi) from it. It has erupted six times since the 1812 eruption; 1883, 1935, 1964-65, 1976, 1986. and 2006. The 1976 and 1986 eruptions started with a series of vent-clearing explosions. There were clouds of volcanic ash that went straight up into the sky. These were followed by eruptions of rocks and mud slides down the side of the volcano. In 1812, 1935, 1964-65, 1976, and 1986, unlike some prehistoric eruptions, the top of the mountain did not collapse. However, in the 1883 eruption, a part of the top of the volcano broke loose starting an avalanche that flowed down to the sea. The avalanche started a small tsunami that reached the Kenai Peninsula at English Bay, 90 kilometres (56 mi) east of the volcano.
Clouds of volcanic ash are a major problem to jet aircraft using Anchorage International and other local airports. Ashfall from future eruptions could disrupt oil and gas operations and shipping activities in Cook Inlet. Eruptions like the historical and prehistoric eruptions are likely in Augustine's future.