BackgroundOne of the northernmost areas of Quaternary volcanism in North America, the Espenberg volcanic field, is located at the northern tip of the Seward Peninsula just south of the Arctic Circle. The five maars, the largest known on Earth, were erupted through thick permafrost during the late Pleistocene. They were at one time considered to have been active into the Holocene (from about 120,000 to about 7000 years ago), but later radiocarbon dating indicated that the youngest maar, Devil Mountain, erupted about 17,500 years ago (Begét et al., 1996). The compound Devil Mountain maar, consisting of two intersecting craters, is 8 x 6 km wide, and North and South Killeak maars are 4 and 5 km wide, respectively. Whitefish maar is 4.3 km wide. The maars were excavated 100-300 m below the ground surface, with lake surfaces 60-80 m below the surrounding topography. The late-Pleistocene basaltic field also contains five older small shield-like volcanoes.
Source: Smithsonian / GVP volcano information
See also: Sentinel hub | Landsat 8