Ushishur

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 47.52°N
  • 152.8°E

  • 401 m
    1315 ft

  • 290210
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: March 1989 (SEAN 14:03)


Highly active fumaroles in the S part of the caldera

Two groups of highly active fumaroles were observed in the S part of the caldera during a 14 January aerial inspection. In autumn 1988, land observations showed solfataric activity, pressurized gas emission, and sulfur deposits within a 170 x 50 m area. Gas temperatures were 100-104°C.

Information Contacts: G. Steinberg, Yuzhno-Sakhalinsk.

The Global Volcanism Program has no Weekly Reports available for Ushishur.

Index of Bulletin Reports


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

12/1981 (SEAN 06:12) Weak gas release from S part of caldera

04/1987 (SEAN 12:04) Fumarolic activity

03/1989 (SEAN 14:03) Highly active fumaroles in the S part of the caldera




Bulletin Reports

All information contained in these reports is preliminary and subject to change.


12/1981 (SEAN 06:12) Weak gas release from S part of caldera

Weak gas release was occurring inside the S part of the caldera [during the 20 September overflight].

Information Contacts: G. Steinberg, Sakhalin Complex Institute.
Download or Cite this Report

04/1987 (SEAN 12:04) Fumarolic activity

Moderate fumarolic activity was noted in the crater and on the W outer slope during 11 and 31 aerial October observations.

Information Contacts: G. Steinberg and B. Piskunov, Yuzhno-Sakhalinsk.
Download or Cite this Report

03/1989 (SEAN 14:03) Highly active fumaroles in the S part of the caldera

Two groups of highly active fumaroles were observed in the S part of the caldera during a 14 January aerial inspection. In autumn 1988, land observations showed solfataric activity, pressurized gas emission, and sulfur deposits within a 170 x 50 m area. Gas temperatures were 100-104°C.

Information Contacts: G. Steinberg, Yuzhno-Sakhalinsk.
Download or Cite this Report

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.

Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1884 Jul Unknown Confirmed 1 Historical Observations SE caldera wall
1769 (after) Unknown Confirmed   Historical Observations Center of caldera bay
1710 ± 10 years Unknown Confirmed 1 Historical Observations SE caldera wall
7450 BCE ± 50 years Unknown Confirmed 4 Radiocarbon (uncorrected)

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.


Synonyms

Ushishiru | Usisiru | Usasyr | Yankicha | Ryponkicha
A small but spectacular caldera truncates the summit of Ushishur volcano. The 1.6-km-wide caldera formed about 9400 years ago and is narrowly breached on the south, allowing sea water to fill the caldera. Four lava domes (three of which are visible here) were constructed within the caldera. Two younger domes, erupted 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.

Photo by Yoshihiro Ishizuka, 2000 (Hokkaido University).
Carbon beneath pumice-fall deposits associated with formation of the small 1.6-km-wide Ushishur caldera were radiocarbon dated at about 9400 years ago. The highest part of the caldera rim (upper right) rises to about 400 m above sea level on the NW side of the shallow caldera bay. The small island at the left was formed during historical time.

Photo by Yoshihiro Ishizuka, 2000 (Hokkaido University).
The two islands in the center of the caldera bay of Ushishur volcano are lava domes that were emplaced sometime after the 1769 visit of Captain Chernyi. The two domes rise less than 100 m above the shallow caldera floor (measured at 58 m depth by Caption Snow). The closest island is 200 x 300 m wide and 32 m high; the smaller one to its left is 100 x 200 wide and 12 m high. The sharp-topped peak at the end of the spit at the left is one of two older lava domes.

Photo by Yoshihiro Ishizuka, 2000 (Hokkaido University).
A phreatic explosion from the fumarolic area at the lower left took place in July 1884. This fumarolic area at the foot of the SE caldera wall contains hot springs that were a sacred place to 18th-19th century Ainu. The caldera rim of Ushishur volcano is breached on the south side by a 300-m-wide gap, which allows sea water to flood the caldera floor. The sharp peak at the left center is one of two older lava domes connected by a grass-mantled sand bar to the SE caldera wall. Ketoi Island (right) is visible in the distance to the SW.

Photo by Yoshihiro Ishizuka, 2000 (Hokkaido University).
The small, but spectacular caldera of Ushishur volcano is breached on its southern side. The 1.6-km-wide caldera was formed during an eruption about 9400 years ago. Two post-caldera lava domes, erupted sometime after the 1769 visit of Captain Snow, form islands in the caldera bay. Two older domes in front of the islands are joined by a sand bar to the SE caldera wall. A northern island (top) to the north consists of a portion of the volcano's flanks.

Photo by R. Bulgakov, 1990 (Institute of Marine Geology and Geophysics, Yuzhno-Sakhalin).

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. 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.

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).

Volcano Types

Caldera
Lava dome(s)

Tectonic Setting

Subduction zone
Oceanic crust (< 15 km)

Rock Types

Major
Andesite / Basaltic Andesite
Dacite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
0
0
16
275

Affiliated Databases

Large Eruptions of Ushishur Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.