Data from the Global Volcanism Program of the Smithsonian Institution
Details for: Izu-Oshima
A steam plume rises from the crater of Mihara-yama on Oshima island. Mihara-yama lies within a 4-km-wide caldera, whose rim is prominently visible in this aerial photo from the SW. Dark-colored lava flows from the 1986 eruption cover part of the caldera floor north of Mihara-yama. More than 40 parasitic cones are located within the caldera and along two parallel rift zones trending NNW-SSE across the island. The port city of Motomachi on the west coast is at the left and the island's airport is at the upper left. Photo by Ichio Moriya (Kanazawa University).
Volcano Number:284010
Volcano Name:Izu-Oshima
Country:Japan
Volcano Type:Stratovolcano
Last Eruption:1990
Elevation:758m
Tectonic Setting:Subduction zone / Oceanic crust (< 15 km)
Pop. within 5km:2381
Pop. within 10km:8037
Pop. within 30km:8375
Pop. within 100km:11837468
Latitude:34.724
Longitude:139.394


Eruption Data from the Global Volcanism Program of the Smithsonian Institution
Volcano Number Volcano Name Eruption Number Activity Type Explosivity Index Max Explosivity Index Modifier Activity Area Activity Unit Start Evidence Method Start Date End Date
284010 Izu-Oshima 18037 Confirmed Eruption 1 Mihara-yama Historical Observations 1965/11/25 1966/6/13
284010 Izu-Oshima 18138 Confirmed Eruption Tephra layer O47 Tephrochronology -8450
284010 Izu-Oshima 18139 Confirmed Eruption Tephra layers O46, O45 Tephrochronology -8050
284010 Izu-Oshima 18140 Confirmed Eruption Tephra layer O44 Tephrochronology -7650
284010 Izu-Oshima 18141 Confirmed Eruption Tephra layers O43, O42 Tephrochronology -7150
284010 Izu-Oshima 18142 Confirmed Eruption Tephra layer O41 Tephrochronology -6650
284010 Izu-Oshima 18143 Confirmed Eruption Tephra layer O40 Tephrochronology -6550
284010 Izu-Oshima 18144 Confirmed Eruption Tephra layers Osb39-2 to Osb38-1 Tephrochronology -6050
284010 Izu-Oshima 18145 Confirmed Eruption Tephra layer Osb37-5 Tephrochronology -5550
284010 Izu-Oshima 18146 Confirmed Eruption Tephra layers Osb37-4, Osb37-3 Tephrochronology -5450
284010 Izu-Oshima 18147 Confirmed Eruption Tephra layers Osb37-2, Osb36-1 Tephrochronology -4920
284010 Izu-Oshima 18148 Confirmed Eruption Tephra layer O35 Tephrochronology -4450
284010 Izu-Oshima 18149 Confirmed Eruption Tephra layer O34 Tephrochronology -4250
284010 Izu-Oshima 18150 Confirmed Eruption Tephra layers O32-2, O32-1, and O32 Tephrochronology -4000
284010 Izu-Oshima 18151 Confirmed Eruption Tephra layer O31 Tephrochronology -3750
284010 Izu-Oshima 18152 Confirmed Eruption Tephra layer O30 Tephrochronology -3650
284010 Izu-Oshima 18153 Confirmed Eruption Tephra layers O29 to O16 Tephrochronology -2550
284010 Izu-Oshima 18154 Confirmed Eruption Tephra layer O15 Tephrochronology -1450
284010 Izu-Oshima 18155 Confirmed Eruption Tephra layer O14 Tephrochronology -1200
284010 Izu-Oshima 18156 Confirmed Eruption Tephra layers O13 to O11 Tephrochronology -1050
284010 Izu-Oshima 18157 Confirmed Eruption 2 SE flank Tephra layer O10 Radiocarbon (corrected) -900
284010 Izu-Oshima 18158 Confirmed Eruption 3 Tephra layers O9 to O5 Tephrochronology -600
284010 Izu-Oshima 18159 Confirmed Eruption 3 Tephra layers O4, O3 Tephrochronology -150
284010 Izu-Oshima 18160 Confirmed Eruption 3 Tephra layer O2 Radiocarbon (corrected) 150
284010 Izu-Oshima 18161 Confirmed Eruption 3 Tephra layer O1 Tephrochronology 250
284010 Izu-Oshima 18162 Confirmed Eruption 4 Summit and east flank Tephra layer S2 Radiocarbon (corrected) 340
284010 Izu-Oshima 18163 Confirmed Eruption 3 Tephra layer S1.5 Varve Count 580
284010 Izu-Oshima 18164 Confirmed Eruption 3 Tephra layer S1 Varve Count 600
284010 Izu-Oshima 18165 Confirmed Eruption 3 Tephra layer N4.8 Varve Count 625
284010 Izu-Oshima 18166 Confirmed Eruption 3 Tephra layer N4.6? Historical Observations 654
284010 Izu-Oshima 18167 Confirmed Eruption 4 Tephra layer N4.4? Historical Observations 680 681/3/26
284010 Izu-Oshima 18168 Confirmed Eruption Historical Observations 684/11/29
284010 Izu-Oshima 18169 Confirmed Eruption 3 Tephra layer N4.2 Varve Count 700
284010 Izu-Oshima 18170 Confirmed Eruption 3 Summit, N & S flanks Tephra layer N4 Varve Count 713
284010 Izu-Oshima 18171 Confirmed Eruption 3 Tephra layer N3.2 Varve Count 822
284010 Izu-Oshima 18172 Confirmed Eruption 3 Summit, SE flank Tephra layer N3.0 Historical Observations 838
284010 Izu-Oshima 18173 Confirmed Eruption 4 Tephra layer N2.0? Historical Observations 854/9/14 856
284010 Izu-Oshima 18174 Confirmed Eruption 4 Tephra layer N1.0? Historical Observations 886/6/29
284010 Izu-Oshima 18175 Uncertain Eruption 936
284010 Izu-Oshima 18176 Uncertain Eruption 1112/11/18 1112/12/26
284010 Izu-Oshima 18177 Confirmed Eruption 4 Tephra layer Y6 Varve Count 1183
284010 Izu-Oshima 18178 Confirmed Eruption 1 Tephra layer Y5.6 Varve Count 1245
284010 Izu-Oshima 18179 Confirmed Eruption 3 NW flank Tephra layer Y5.2 Varve Count 1307
284010 Izu-Oshima 18180 Confirmed Eruption 3 Tephra layer 5 Historical Observations 1338/9/15 1338/11/15
284010 Izu-Oshima 18181 Confirmed Eruption Historical Observations 1415/5/21
284010 Izu-Oshima 18182 Confirmed Eruption 2 Tephra layer 4.2 Historical Observations 1416/9/2 1417
284010 Izu-Oshima 18183 Confirmed Eruption 4 Summit, S flank Tephra layer Y4 Historical Observations 1421/5/14
284010 Izu-Oshima 18184 Confirmed Eruption Historical Observations 1442 1443
284010 Izu-Oshima 18185 Confirmed Eruption 2 Tephra layer Y3.8 Varve Count 1471
284010 Izu-Oshima 18186 Confirmed Eruption 3 Historical Observations 1552/10/7 1552/10/15
284010 Izu-Oshima 18187 Confirmed Eruption Historical Observations 1600
284010 Izu-Oshima 18188 Confirmed Eruption Historical Observations 1612/10/15
284010 Izu-Oshima 18189 Confirmed Eruption Historical Observations 1623
284010 Izu-Oshima 18190 Confirmed Eruption Historical Observations 1634
284010 Izu-Oshima 18191 Confirmed Eruption Historical Observations 1637/8/26 1638
284010 Izu-Oshima 18192 Confirmed Eruption 3 Tephra layer Y2 Historical Observations 1684/2/14 1690
284010 Izu-Oshima 18193 Confirmed Eruption Historical Observations 1695/4/12
284010 Izu-Oshima 18194 Confirmed Eruption 3 Mihara-yama & flanks Tephra layer Y1 Historical Observations 1777/8/31 1779
284010 Izu-Oshima 18195 Confirmed Eruption 2 Mihara-yama Historical Observations 1783 1786
284010 Izu-Oshima 18196 Confirmed Eruption 2 Mihara-yama Historical Observations 1789
284010 Izu-Oshima 18197 Confirmed Eruption 2 Mihara-yama Historical Observations 1792
284010 Izu-Oshima 18198 Confirmed Eruption 2 Mihara-yama Historical Observations 1803/9/26 1803/11/14
284010 Izu-Oshima 18199 Confirmed Eruption 3 Yephra layer Y0.8 Varve Count 1821
284010 Izu-Oshima 18200 Confirmed Eruption 2 Mihara-yama Historical Observations 1822 1824
284010 Izu-Oshima 18201 Uncertain Eruption Mihara-yama 1827
284010 Izu-Oshima 18202 Uncertain Eruption 2 Mihara-yama 1837 1838
284010 Izu-Oshima 18203 Confirmed Eruption 2 Mihara-yama Historical Observations 1846
284010 Izu-Oshima 18204 Uncertain Eruption Mihara-yama 1868/12/31
284010 Izu-Oshima 18205 Confirmed Eruption 2 Mihara-yama Historical Observations 1870
284010 Izu-Oshima 18206 Confirmed Eruption 2 Mihara-yama Historical Observations 1876/12/27 1877/2/5
284010 Izu-Oshima 18207 Confirmed Eruption 1 Mihara-yama Historical Observations 1910
284010 Izu-Oshima 18208 Confirmed Eruption 1 Mihara-yama Historical Observations 1912/2/23 1913/1/25
284010 Izu-Oshima 18209 Confirmed Eruption 2 Mihara-yama Historical Observations 1914/5/15 1914/5/26
284010 Izu-Oshima 18210 Confirmed Eruption 2 Mihara-yama Historical Observations 1915/10/10 1915/10/25
284010 Izu-Oshima 18211 Confirmed Eruption 0 Mihara-yama Historical Observations 1919/5/18 1919/12/23
284010 Izu-Oshima 18212 Uncertain Eruption Mihara-yama 1920
284010 Izu-Oshima 18213 Confirmed Eruption 1 Mihara-yama Historical Observations 1922/12/8 1923/1/30
284010 Izu-Oshima 18214 Confirmed Eruption 2 Mihara-yama Historical Observations 1928/8/7 1928/8/8
284010 Izu-Oshima 18215 Confirmed Eruption 0 Mihara-yama Historical Observations 1933/10/14 1933
284010 Izu-Oshima 18216 Confirmed Eruption 0 Mihara-yama Historical Observations 1934/4/15 1934/4/25
284010 Izu-Oshima 18217 Uncertain Eruption Mihara-yama 1934
284010 Izu-Oshima 18218 Confirmed Eruption 0 Mihara-yama Historical Observations 1935/4/26 1935/5/6
284010 Izu-Oshima 18219 Confirmed Eruption 0 Mihara-yama Historical Observations 1937/7/17 1937
284010 Izu-Oshima 18220 Confirmed Eruption 1 Mihara-yama Historical Observations 1938/8/11 1938/8/11
284010 Izu-Oshima 18221 Confirmed Eruption 1 ? Mihara-yama Historical Observations 1939 1939
284010 Izu-Oshima 18222 Confirmed Eruption 1 Mihara-yama Historical Observations 1939/9/1 1939/9/16
284010 Izu-Oshima 18223 Confirmed Eruption 1 Mihara-yama Historical Observations 1940/8/18 1940/8/19
284010 Izu-Oshima 18224 Confirmed Eruption 2 Mihara-yama, south rim Historical Observations 1950/7/16 1951/6/28
284010 Izu-Oshima 18225 Confirmed Eruption 1 Mihara-yama Historical Observations 1953/10/5 1954/2/8
284010 Izu-Oshima 18226 Confirmed Eruption 1 Mihara-yama Historical Observations 1956/1/3 1956/1/6
284010 Izu-Oshima 18227 Uncertain Eruption 1 ? Mihara-yama 1956/8/25 1956/8/26
284010 Izu-Oshima 18228 Confirmed Eruption 1 Mihara-yama Historical Observations 1957/8/16 1957/12/16
284010 Izu-Oshima 18229 Confirmed Eruption 1 Mihara-yama Historical Observations 1958/4/17 1958/6/13
284010 Izu-Oshima 18230 Confirmed Eruption 1 Mihara-yama Historical Observations 1959/1/16 1959/1/16
284010 Izu-Oshima 18231 Confirmed Eruption 1 Mihara-yama Historical Observations 1959/10/16 1960/11/16
284010 Izu-Oshima 18232 Uncertain Eruption Mihara-yama 1961/7/2
284010 Izu-Oshima 18233 Confirmed Eruption 1 Mihara-yama Historical Observations 1962/1/16 1965/5/16
284010 Izu-Oshima 18234 Confirmed Eruption 1 Mihara-yama Historical Observations 1967/5/16 1967/8/16
284010 Izu-Oshima 18235 Confirmed Eruption 1 Mihara-yama Historical Observations 1968/1/19 1968/1/19
284010 Izu-Oshima 18236 Confirmed Eruption 1 Mihara-yama Historical Observations 1968/7/28 1968/7/28
284010 Izu-Oshima 18237 Confirmed Eruption 1 Mihara-yama Historical Observations 1969/1/19 1969/7/16
284010 Izu-Oshima 18238 Confirmed Eruption 1 Mihara-yama Historical Observations 1970/1/26 1970/1/31
284010 Izu-Oshima 18239 Confirmed Eruption 1 Mihara-yama Historical Observations 1970/6/30 1970/11/12
284010 Izu-Oshima 18240 Confirmed Eruption 1 Mihara-yama Historical Observations 1971/4/5 1971/4/5
284010 Izu-Oshima 18241 Confirmed Eruption 1 Mihara-yama Historical Observations 1974/2/28 1974/6/20
284010 Izu-Oshima 18242 Confirmed Eruption 3 Mihara-yama, N part and NW of caldera Historical Observations 1986/11/15 1986/12/18
284010 Izu-Oshima 18243 Confirmed Eruption 2 Mihara-yama Historical Observations 1987/11/16 1988/1/27
284010 Izu-Oshima 18244 Confirmed Eruption 2 Mihara-yama (1987 summit crater) Historical Observations 1990/10/4 1990/10/4
Emissions Data from the Global Volcanism Program of the Smithsonian Institution
Emission ID SO2 Kilotons Start Date End Date
170 22 1986/11/19 1986/11/19

Data from the Earthchem Portal

Data from the SESAR Database

Data from the MaGa Database
Location: Ohtsu Well (View Details at MaGa DB)
Description: unknown
Hazard Description: unknown
Type: well
Region: Tokyo, Japan
Country: Japan
Volcanic Complex: Oshima
Gas Concentration Data:
Measurement Name Detail Specie Concentration Unit of Measure
Oht-1 Detail CO2 902.26 micromol/mol
Oht-1 Detail S (total) 55.35 micromol/mol
Oht-1 Detail SO2 35.41 micromol/mol
Oht-1 Detail H2S 19.83 micromol/mol
Oht-1 Detail HF 9.608 micromol/mol
Oht-1 Detail NH3 0.725 micromol/mol
Oht-1 Detail Ar 0.49 micromol/mol
Oht-1 Detail N2 20.993 micromol/mol
Oht-1 Detail He 0 micromol/mol
Oht-1 Detail H2 0.011 micromol/mol
Oht-1 Detail O2 10.558 micromol/mol
Oht-1 Detail CH4 0 micromol/mol
Oht-1 Detail CO 0 micromol/mol
Gas Isotope Data:
Measurement Name Detail Isotope Abundance Unit of Measure
Oht-1 Detail d15N 0 permill_vs_smow
Gas Temperature Data:
Measurement Name Detail Temperature Unit of Measure
Oht-1 Detail 36.4 °C
Location: Koshimizu Well (View Details at MaGa DB)
Description: unknown
Hazard Description: unknown
Type: well
Region: Tokyo, Japan
Country: Japan
Volcanic Complex: Oshima
Gas Concentration Data:
Measurement Name Detail Specie Concentration Unit of Measure
Kos-1 Detail CO2 881.82 micromol/mol
Kos-1 Detail S (total) 71.69 micromol/mol
Kos-1 Detail SO2 62.14 micromol/mol
Kos-1 Detail H2S 9.45 micromol/mol
Kos-1 Detail HF 10.3 micromol/mol
Kos-1 Detail NH3 0.809 micromol/mol
Kos-1 Detail Ar 0.588 micromol/mol
Kos-1 Detail N2 25.399 micromol/mol
Kos-1 Detail He 0 micromol/mol
Kos-1 Detail H2 0.01 micromol/mol
Kos-1 Detail O2 9.38 micromol/mol
Kos-1 Detail CH4 0 micromol/mol
Kos-1 Detail CO 0 micromol/mol
Gas Isotope Data:
Measurement Name Detail Isotope Abundance Unit of Measure
Kos-1 Detail d15N -0.6 permill_vs_smow
Gas Temperature Data:
Measurement Name Detail Temperature Unit of Measure
Kos-1 Detail 48.5 °C
Location: Univ. of Tokyo Obs. Well (View Details at MaGa DB)
Description: unknown
Hazard Description: unknown
Type: well
Region: Tokyo, Japan
Country: Japan
Volcanic Complex: Oshima
Gas Concentration Data:
Measurement Name Detail Specie Concentration Unit of Measure
Uto-1 Detail H2O 744.81 micromol/mol
Uto-1 Detail CO2 521.88 micromol/mol
Uto-1 Detail S (total) 1.13 micromol/mol
Uto-1 Detail H2S 1.13 micromol/mol
Uto-1 Detail HCl 10.32 micromol/mol
Uto-1 Detail HF 1.467 micromol/mol
Uto-1 Detail NH3 1.105 micromol/mol
Uto-1 Detail Ar 4.661 micromol/mol
Uto-1 Detail N2 384.388 micromol/mol
Uto-1 Detail He 0 micromol/mol
Uto-1 Detail H2 0.026 micromol/mol
Uto-1 Detail O2 75.02 micromol/mol
Uto-1 Detail CH4 0 micromol/mol
Uto-1 Detail CO 0 micromol/mol
Uto-2 Detail H2O 416.51 micromol/mol
Uto-2 Detail CO2 344.06 micromol/mol
Uto-2 Detail S (total) 0.48 micromol/mol
Uto-2 Detail H2S 0.48 micromol/mol
Uto-2 Detail HCl 4.202 micromol/mol
Uto-2 Detail HF 0.346 micromol/mol
Uto-2 Detail NH3 0.201 micromol/mol
Uto-2 Detail Ar 6.529 micromol/mol
Uto-2 Detail N2 540.343 micromol/mol
Uto-2 Detail He 0 micromol/mol
Uto-2 Detail H2 0.019 micromol/mol
Uto-2 Detail O2 103.814 micromol/mol
Uto-2 Detail CH4 0 micromol/mol
Uto-2 Detail CO 0 micromol/mol
Gas Isotope Data:
Measurement Name Detail Isotope Abundance Unit of Measure
Uto-1 Detail d15N 0.9 permill_vs_smow
Uto-2 Detail d15N 0.9 permill_vs_smow
Gas Temperature Data:
Measurement Name Detail Temperature Unit of Measure
Uto-1 Detail 81 °C
Uto-2 Detail 81 °C
Location: Hotel Onsen Well (View Details at MaGa DB)
Description: unknown
Hazard Description: unknown
Type: well
Region: Tokyo, Japan
Country: Japan
Volcanic Complex: Oshima
Gas Concentration Data:
Measurement Name Detail Specie Concentration Unit of Measure
Ons-1 Detail CO2 965.75 micromol/mol
Ons-1 Detail S (total) 12.76 micromol/mol
Ons-1 Detail H2S 12.76 micromol/mol
Ons-1 Detail HF 3.316 micromol/mol
Ons-1 Detail NH3 1.364 micromol/mol
Ons-1 Detail Ar 0.289 micromol/mol
Ons-1 Detail N2 12.368 micromol/mol
Ons-1 Detail He 0 micromol/mol
Ons-1 Detail H2 0.126 micromol/mol
Ons-1 Detail O2 3.918 micromol/mol
Ons-1 Detail CH4