BackgroundThe 2.9-km-wide Apas caldera was the source of block-and-ash flows, pumice flows, and ash flows that extend primarily to the SW and NW. The SW deposit forms a large fan covering about 140 km2. Deposits from the Apas collapse structure were K-Ar dated at about 0.432 million years. The 1.34-km-wide Pleistocene Navenchauc explosion crater lies immediately NE of the Apas caldera. The Navenchauc lava dome was constructed on the northern rim of the Navenchauc caldera.
Source: Smithsonian / GVP volcano information
See also: Sentinel hub | Landsat 8