The Karymsky stratovolcano stands 1,536 meters (5,039 feet) above sea level, and most of its eruptions and occasional lava flows originate from the summit. Karymsky is the most active of Kamchatka’s eastern volcanoes, with almost constant (on a geologic time scale) volcanism occurring since at least the late 18th century, when the historical record for the region began.
Because of the high levels of volcanic activity on the Kamchatka Peninsula, the Kamchatka Volcanic Eruption Response Team (KVERT) monitors the activity levels of several volcanoes and issues updates including aviation alerts and webcams. KVERT reported moderate seismic activity at Karymsky between November 2–9, 2012. Such activity can indicate the movement of magma beneath or within a volcanic structure and that an eruption may be imminent. The Tokyo Volcanic Ash Advisory Center (VAAC) subsequently reported an explosive eruption at Karymsky on November 9 at 22:15 Universal Time.
This astronaut photograph of the resulting ash plume was taken approximately 1 hour and 35 minutes after the eruption began. The plume extends from the summit of Karymsky to the southeast, with brown ash deposits darkening the snow cover below the plume.
The Akademia Nauk caldera—now filled with water to form the present-day Karymsky Lake—is located to the south of Karymsky volcano. Calderas are formed by explosive eruption and emptying of a volcano’s magma chamber, leading to collapse of the structure to form a crater-like depression. Akademia Nauk last erupted in 1996.