BackgroundThe Ugashik-Peulik volcanic complex lies south of Becharof Lake and east of Upper Ugashik Lake. Late-Pleistocene caldera formation at Ugashik volcano was followed by the emplacement of at least 5 Holocene lava domes within the 4.5-km-wide caldera. Most of the caldera walls consist of basement sandstones of Jurassic age. Following caldera formation the small, 3 cu km Peulik stratovolcano grew 2.5 km to the north to a height of 1474 m, more than 500 m above that of Ugashik. Lava flows from Peulik cover the caldera rim to the south and extend to Becharof Lake, 6 km to the north. A small lava dome at 1200 m elevation on the east flank of Peulik was the source of a small block-and-ash flow. The summit of Peulik volcano contains a 1.5-km-wide crater breached to the west that is partially filled by a lava dome. Debris-avalanche deposits cover a 75 sq km area to the NW. A single documented historical eruption took place from Peulik volcano in 1814.
Smithsonian / GVP volcano information
See also: Sentinel hub | Landsat 8