A lava dome on the north side of Mount Redoubt steams on Thursday, June 21, 2012, in Lake Clark National Park and Preserve, Alaska. The lava dome, which is still cooling from its 2009 eruption, is about 3300 feet in length, 1600 feet wide and averages 660 feet in thickness, according to vulcanologist Tina Neal of the Alaska Volcano Observatory. Redoubt has been quiet since its last eruption, which began in March of 2009 and lasted for nearly four months and resulted in ash fall on the Kenai Peninsula and the Anchorage area. Prior to 2009, the volcano had last erupted in 1989, and included one explosion that famously crippled a jet inbound for Anchorage. Redoubt is one of four active volcanoes in the Cook Inlet region. The others are Spurr, Iliamna and Augustine. Current info on all Alaska volcanoes can be found on the Alaska Volcano Observatory website.