BackgroundMassive dissected Mount Sanford shield volcano is one of the highest Quaternary volcanoes in the United States. The 4949-m-high, glacier-covered andesitic volcano towers above the Copper River and has a broad, bulbous top that is surrounded by massive, glacially excavated cirques, most prominent on the SW and SE sides of the summit. The upper part of this little-studied, ice-covered volcano is possibly of Holocene age (Richter, in Wood and Kienle, 1990) and developed on a base of three coalescing andesitic shield volcanoes south, NW and NNW of the summit that began to form about 900,000 years ago. A massive mid-Pleistocene rhyolitic lava flow from a NE-flank vent traveled more than 18 km to the NE. Basaltic lava flows that were erupted from a NE-flank rift zone about 320,000 years ago mark the latest radiometrically dated activity from Mount Sanford.
Smithsonian / GVP volcano information
See also: Sentinel hub | Landsat 8