No latest activity reported for Ushishur.

Below is a summary of eruption dates and Volcanic Explosivity Indices (VEI).

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Gorshkov G S, 1958. Kurile Islands. {Catalog of Active Volcanoes of the World and Solfatara Fields}, Rome: IAVCEI, 7: 1-99

Gorshkov G S, 1970. {Volcanism and the Upper Mantle; Investigations in the Kurile Island Arc}. New York: Plenum Publishing Corp, 385 p

Sazonov A P, Gavrilenko G M, 1995. Lithology and geochemistry of bottom sediments in the crater bay, Ushishir volcanic island, Kuril Islands. {Volc Seism}, 16: 387-400 (English translation)

The subaerial portion of Ushishur volcano in the central Kuriles is exposed in two small islands, the southern containing the summit caldera and the northern a portion of the volcano's flanks. A small 1.6-km-wide caldera that formed about 9400 years ago is narrowly breached on the south, allowing sea water to fill the caldera. Two andesitic lava domes occupy part of the caldera bay; two other older domes are joined by a sand bar to the SE caldera wall. The two younger domes, erupted sometime after the 1769 visit of Captain Snow, form islands in the bay. A cluster of strong fumaroles and hot springs along the SE caldera shoreline was a sacred place to 18th- and 19th-century Kurile Ainu peoples, and vigorous submarine hydrothermal activity has modified the geochemistry of sea water within the caldera bay. Aside from growth of the two younger lava domes, only minor phreatic eruptions have occurred at Ushishur during historical time.