Somma volcano

Aerial view of Fogo Island, Cape Verde, an example of a somma volcano. The volcanic cone Pico do Fogo rises 100m above the walls of the caldera.

A somma volcano (also known 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)
  • Krakatoa Group (Lampung, Indonesia): a partially-submerged somma volcano
  • 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)