The volcanoes reside on the Kamchatka Peninsula in Russia, an active volcanic area much like the rest of the Pacific Ring of Fire.
Klyuchevskaya, also called Kliuchevskoi, is a monstrous mountain reaching 15,860 feet (4,835 meters) – the tallest volcano in Kamchatka. According to NASA, it has erupted more than 80 times in the last 300 years. In the fall of 1994 it shot a plume of ash more than one mile high and was easily seen by astronauts on the Space Shuttle Endeavor.
Bezymianny, at only 9,455 feet (2,882 meters), was imaged in by NASA back in November during a prior eruption. It was thought to be extinct until it erupted from 1955 to 1956. Prior to that, it had experienced a period of 1,000 years of dormancy. The 1956 eruption was comparable in size to the Mount Saint Helens eruption in 1980 and resulted in a horseshoe shaped crater that has since been filled by other, smaller eruptions and pyroclastic flows.