Ksudach , also known as Stubel volcano or Voniuchi Khrebet, is a caldera volcano that is well known for its great eruption of 1907. At the bottom of this caldera is located two lakes Bolshoe (meaning: big in Russian) and Kraternoe (meaning: cratered in Russian). Kraternoe occupies the 1907 eruption crater, Stubel, and is the headwaters of the Khodutka river while other lake has not outlet.
Scientists believe that Ksudach caldera itself lies within a huge ancient caldera. KsudachUs caldera is circular and has a diameter of about 7 km. Several smaller caldera, 3-5 km across, can be found in the northern part of this caldera. The active strato-cone, Stubel is located in the northernmost caldera and a part of a linear chain of small lava volcanoes and cinder cones that cut across this northern portion of the caldera.
Sources of Information:
Vlodavetz V.I., Piip B. I. 1959 Kamchatka and Continental Areas of Asia. Catalog of Active Volcanoes of the World, Rome IAVCEI, 8: p11-15.
Erlich, Edward 1986 Geology of Calderas of Kamchatka and Kurile Islands with Comparison to Calderas of Japan and the Aleutians, Alaska Open-File Report 86-291, US Dept. of the Interior- Geological Survey, p103-6.