Iwatesan

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  • Japan
  • Honshu
  • Complex
  • 1919 CE
  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 39.853°N
  • 141.001°E

  • 2038 m
    6685 ft

  • 283240
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

There are no activity reports for Iwatesan.



 Available Weekly Reports

There are no Weekly Reports available for Iwatesan.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
[ 1934 Jul ] [ 1935 ] Uncertain    
1919 Jul 15 (?) 1919 Jul 15 (?) Confirmed 1 Historical Observations W side of Onigajo caldera (O-jigokudani)
[ 1823 ] [ Unknown ] Discredited    
1732 Jan 22 1732 Oct (?) Confirmed 2 Historical Observations NE flank of Yakushi-dake
[ 1719 Feb (?) ] [ Unknown ] Discredited    
[ 1689 Jun 22 ] [ Unknown ] Uncertain 2  
[ 1687 Apr 14 ] [ 1687 Jul ] Uncertain 2  
1686 Mar 26 1686 Mar 27 Confirmed 3 Historical Observations
1450 ± 100 years Unknown Confirmed   Radiocarbon (uncorrected) Nishi-Iwate and Higashi-Iwate
1300 ± 50 years Unknown Confirmed 3 Tephrochronology Higashi-Iwate (Myoko-dake)
0150 (?) Unknown Confirmed   Radiocarbon (uncorrected) Higashi-Iwate
0350 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected) Higashi-Iwate
0450 BCE (?) Unknown Confirmed   Radiocarbon (corrected) Nishi-Iwate (O-jigokudani area)
1150 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected) Nishi-Iwate
1250 BCE (?) Unknown Confirmed 3 Radiocarbon (corrected) Higashi-Iwate
1500 BCE ± 300 years Unknown Confirmed   Tephrochronology Higashi-Iwate
1650 BCE (?) Unknown Confirmed   Radiocarbon (corrected) Nishi-Iwate (O-jigokudani area)
2000 BCE (?) Unknown Confirmed   Radiocarbon (corrected) Nishi-yama
2050 BCE ± 200 years Unknown Confirmed   Radiocarbon (corrected) Higashi-Iwate, W5 tephra
2700 BCE ± 200 years Unknown Confirmed   Tephrochronology Higashi-Iwate, W6a-d tephras
2950 BCE ± 50 years Unknown Confirmed   Radiocarbon (corrected) Nishi-Iwate, PHD5 tephra
3050 BCE (?) Unknown Confirmed   Radiocarbon (uncorrected) Higashi-Iwate
3250 BCE ± 500 years Unknown Confirmed 0 Tephrochronology
3750 BCE ± 100 years Unknown Confirmed   Tephrochronology Higashi-Iwate
4350 BCE ± 500 years Unknown Confirmed   Tephrochronology Higashi-Iwate
4450 BCE ± 500 years Unknown Confirmed 0 Tephrochronology Higashi-Iwate
4850 BCE ± 50 years Unknown Confirmed   Radiocarbon (corrected) Nishi-Iwate, PHD6 tephra
4900 BCE ± 100 years Unknown Confirmed   Radiocarbon (corrected) Higashi-Iwate
5650 BCE ± 50 years Unknown Confirmed   Radiocarbon (corrected) Nishi-Iwate, PHD7 tephra
6300 BCE ± 100 years Unknown Confirmed   Radiocarbon (corrected) Nishi-Iwate, PHD8 tephra
6450 BCE ± 1000 years Unknown Confirmed   Tephrochronology

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.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

Itoh J, 1998. The eruption history of Iwate volcano in the Edo period, based on the historical documents. Bull Volc Soc Japan (Kazan), 43: 467-481 (in Japanese with English abs).

Japan Meteorological Agency, 2013. National Catalogue of the Active Volcanoes in Japan (fourth edition, English version). Japan Meteorological Agency.

Japan Meteorological Agency, 1996. National Catalogue of the Active Volcanoes in Japan (second edition). Tokyo: Japan Meteorological Agency, 502 p (in Japanese).

Kudo T, Hoshizumi H, 2006-. Catalog of eruptive events within the last 10,000 years in Japan, database of Japanese active volcanoes. Geol Surv Japan, AIST, http://riodb02.ibase.aist.go.jp/db099/eruption/index.html.

Kuno H, 1962. Japan, Taiwan and Marianas. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 11: 1-332.

Nakano S, Yamamoto T, Iwaya T, Itoh J, Takada A, 2001-. Quaternary Volcanoes of Japan. Geol Surv Japan, AIST, http://www.aist.go.jp/RIODB/strata/VOL_JP/.

Tanaka S, Hamaguchi H, Ueki S, Sato M, Nakamichi H, 2002. Migration of seismic activity during the 1998 volcanic unrest at Iwate volcano, northeastern Japan, with reference to P and S wave velocity anomaly and crustal deformation. J Volc Geotherm Res, 113: 399-414.

Viewed from the east, Iwatesan volcano has a symmetrical profile that invites comparison with Fuji, but on the west an older cone is visible containing an oval-shaped, 1.8 x 3 km caldera. After the growth of Nishi-Iwate volcano beginning about 700,000 years ago, activity migrated eastward to form Higashi-Iwate volcano. Iwate has collapsed seven times during the past 230,000 years, most recently between 739 and 1615 AD. The dominantly basaltic summit cone of Higashi-Iwate volcano, Yakushidake, is truncated by a 500-m-wide crater. It rises well above and buries the eastern rim of the caldera, which is breached by a narrow gorge on the NW. A central cone containing a 500-m-wide crater partially filled by a lake is located in the center of the oval-shaped caldera. A young lava flow from Yakushidake descended into the caldera, and a fresh-looking lava flow from the 1732 eruption traveled down the NE flank.