A somma volcano (also known simply as a sommian) is a volcanic caldera that has been partially filled by a new central cone. The name comes from Mount Somma, a stratovolcano in southern Italy with a summit caldera in which the upper cone of Mount Vesuvius has grown.
A number of the world's best examples of somma volcanoes are found on Russia's Kamchatka Peninsula and the Kuril Islands that stretch south from Kamchatka to Hokkaidō (Japan).
Some examples of somma volcanoes are the following:
Europe
Mount Vesuvius (Campania, Italy)
Mount Pico, Azores, Portugal
Africa
Teide (Tenerife, Canary Islands, Spain)
Pico do Fogo (Fogo Island, Cape Verde)
Asia
Aira Caldera (Kyūshū, Japan)
Ebeko (Paramushir Island, Kuril Islands, Russia)
Kolokol Group: Kolokol, Berg, Borzov, Trezubetz (Urup Island, Kuril Islands, Russia)
Medvezhya (Iturup Island, Kuril Islands, Russia)
Milna (Simushir Island, Kuril Islands, Russia)
Pinatubo (Central Luzon, Philippines)
Tengger Caldera (East Java, Indonesia)
Tondano Caldera (North Sulawesi, Indonesia)
Tyatya (Kunashir Island, Kuril Islands, Russia)
Urataman (Simushir Island, Kuril Islands, Russia)
Zarechny (Kamchatka Peninsula, Russia)
Americas
Cosigüina (Chinandega, Nicaragua)
Wizard Island (Oregon, United States)
