Novarupta Dome, upper Valley of Ten Thousand Smokes, Katmai National Park and Preserve, Alaska. The 380-m-wide rhyolite lava dome marks the center of the vent of the great eruption of 1912, and formed in the weeks to months following the June 6-9 explosive eruption. The vent itself is roughly 2 km wide and was backfilled by welded ash-flow tuff and fallback ejecta during the eruption. Photo taken during 20 August 2010 gas flight.
Credit: Image courtesy of AVO/USGS.