A somma volcano (also known as a sommian) is a volcanic

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...

that has been partially filled by a new central cone. The name comes from Mount Somma, a

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and per ...

in southern Italy with a summit caldera in which the upper cone of Mount Vesuvius has grown. A number of Earth's best examples of somma volcanoes are found on Russia's Kamchatka Peninsula and the Kuril Islands that stretch south from Kamchatka to

Hokkaidō is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel. The la ...

(Japan). Some examples of somma volcanoes are the following: * Africa ** Pico do Fogo ( Fogo Island, Cape Verde) ** Teide ( Tenerife,

Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...

, Spain) * Americas ** Cosigüina ( Chinandega, Nicaragua) ** Wizard Island ( Oregon, United States) ** Lava domes ( Mount St. Helens, Washington, United States) * Asia ** Ebeko ( Paramushir Island, Kuril Islands, Russia) ** Gunung Baru Jari ( Segara Anak caldera, Lombok, Indonesia) ** Kolokol Group: Kolokol, Berg, Borzov, Trezubetz ( Urup Island, Kuril Islands, Russia) ** Anak Krakatoa ( Krakatoa archipelago,

Sunda Strait The Sunda Strait ( id, Selat Sunda) is the strait between the Indonesian islands of Java island, Java and Sumatra. It connects the Java Sea with the Indian Ocean. Etymology The strait takes its name from the Sunda Kingdom, which ruled the weste ...

, Lampung, Indonesia): a partially-submerged nested somma volcano (with a central cone within a caldera which is itself within a larger caldera). ** Krenitsyn Peak (

Tao-Rusyr caldera Tao-Rusyr Caldera (russian: Тао-Русыр) is a stratovolcano located at the southern end of Onekotan Island, Kuril Islands, Russia. It has 7.5 km wide caldera formed during a catastrophic eruption less than 10,000 years ago (reported a ...

Onekotan Island Onekotan (russian: Онекотан; Japanese 温禰古丹島; Onekotan-tō, occasionally Onnekotan-tō, ain, オネコタン　or　オネコタㇴ) is an uninhabited volcanic island located near the northern end of the Kuril Islands chain in t ...

, Kuril Islands, Russia) **

Medvezhya Medvezhya (russian: Медве́жий; ja, 茂世路岳, ''Moyoro-dake'') is a volcanic complex located at the northern end of Iturup Island, Kuril Islands, Russia. Rheniite, a rhenium sulfide mineral (ReS2), was discovered and approved in 20 ...

( 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) ** Sakurajima ( Aira caldera,

Kyūshū is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surround ...

, Japan) ** Tyatya ( Kunashir Island, Kuril Islands, Russia) **

Urataman Uratman (russian: Уратман) is a somma volcano located at the northern end of Simushir Island, Kuril Islands, Russia. It overlooks the Brouton Bay which is contained within the crater. The volcano consists of a Pleistocene caldera which con ...

( Simushir Island, Kuril Islands, Russia) ** Zarechny (Kamchatka Peninsula, Russia) * Europe ** Nea Kameni ( Santorini caldera, Greece): a partially-submerged somma volcano ** Mount Pico ( Azores, Portugal) ** Mount Vesuvius ( Campania, Italy) * Oceania ** Mount Gharat ( Gaua, Vanuatu)

See also