Zaozan

Photo of this volcano
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 38.144°N
  • 140.44°E

  • 1841 m
    6038 ft

  • 283190
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: September 1992 (BGVN 17:09) Citation IconCite this Report


Earthquake and numerous aftershocks, but no surface changes evident

A seismic shock of M 4.7 occurred at 1758 on 1 September a few kilometers ESE of the summit. The shock was felt at JMA intensity IV near the volcano, and was weakly felt at Sendai (35 km E), Fukushima (45 km S), and Onahama (135 km E). Aftershocks were numerous, but declined toward mid-September. The high seismicity was the first at the volcano since July 1990, when there were many small earthquakes below the summit. Surveys of fumarolic areas on 5 September revealed no changes in temperature from the last survey in 1990.

Information Contacts: JMA.

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

Bulletin Reports - Index


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.

09/1992 (BGVN 17:09) Earthquake and numerous aftershocks, but no surface changes evident




Information is preliminary and subject to change. All times are local (unless otherwise noted)


September 1992 (BGVN 17:09) Citation IconCite this Report


Earthquake and numerous aftershocks, but no surface changes evident

A seismic shock of M 4.7 occurred at 1758 on 1 September a few kilometers ESE of the summit. The shock was felt at JMA intensity IV near the volcano, and was weakly felt at Sendai (35 km E), Fukushima (45 km S), and Onahama (135 km E). Aftershocks were numerous, but declined toward mid-September. The high seismicity was the first at the volcano since July 1990, when there were many small earthquakes below the summit. Surveys of fumarolic areas on 5 September revealed no changes in temperature from the last survey in 1990.

Information Contacts: JMA.

Eruptive History


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


Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1940 May 18 1940 May 18 Confirmed 1 Historical Observations Okama
[ 1939 Jul ] [ Unknown ] Uncertain 1   Okama
[ 1927 ] [ Unknown ] Uncertain 1   Okama
[ 1906 ] [ Unknown ] Discredited    
1905 Unknown Confirmed 1 Historical Observations Okama
[ 1897 Jan 14 ] [ 1897 Jan 14 ] Uncertain 1   Okama
[ 1896 Sep 1 (?) ] [ Unknown ] Uncertain 1   Okama
1896 Mar 8 1896 Mar 8 Confirmed 1 Historical Observations Okama
1895 Aug 22 1895 Sep 28 Confirmed 2 Historical Observations Okama
1895 Feb 15 1895 Mar 22 Confirmed 1 Historical Observations Okama
1894 Jul 3 1894 Jul 3 Confirmed 2 Historical Observations Okama
[ 1890 ] [ Unknown ] Uncertain 1   Okama
1873 Aug 1873 Sep Confirmed 1 Historical Observations Okama
1867 Oct 21 Unknown Confirmed 2 Historical Observations Okama
1833 Unknown Confirmed 2 Historical Observations Okama
1831 Nov 22 Unknown Confirmed 2 Historical Observations Okama
1830 Unknown Confirmed 2 Historical Observations Okama
1822 May 1 Unknown Confirmed   Historical Observations
1821 Jan 27 1821 May 1 Confirmed 2 Historical Observations Okama
1809 Jun 12 1809 Dec 29 Confirmed 2 Historical Observations Okama
1806 Jul 12 Unknown Confirmed 2 Historical Observations Okama
1804 May (?) Unknown Confirmed 2 Historical Observations Okama
1796 Mar 24 Unknown Confirmed 2 Historical Observations Okama
1794 Sep 22 1794 Dec (in or after) Confirmed 2 Historical Observations SE side of Okama
1694 May 29 1694 Aug 30 (?) Confirmed 2 Historical Observations Okama
1670 Apr 26 1670 Sep 26 Confirmed 2 Historical Observations Okama
1669 Unknown Confirmed 3 Historical Observations Okama
1668 Aug Unknown Confirmed 2 Historical Observations Okama
1641 Unknown Confirmed 2 Historical Observations Okama
1630 Unknown Confirmed 2 Historical Observations Okama
1623 May 15 (?) 1624 Nov 15 (?) Confirmed 3 Historical Observations Okama
1622 Unknown Confirmed 2 Historical Observations Okama
1620 Unknown Confirmed 2 Historical Observations Okama
1400 ± 100 years Unknown Confirmed 3 Radiocarbon (corrected) Goshiki-dake area, Z-To11 tephra
[ 1350 (?) ] [ Unknown ] Uncertain 2   Okama
[ 1331 ] [ 1333 ] Uncertain 2   Okama
1230 Nov 29 (?) Unknown Confirmed 2 Historical Observations Okama
1227 Oct (?) Unknown Confirmed 3 Historical Observations Okama
1183 May 28 (?) Unknown Confirmed 2 Historical Observations Okama
0884 (?) Unknown Confirmed 3 Historical Observations Okama, Z-To10 tephra?
[ 0773 Nov (?) ] [ Unknown ] Uncertain     Okama
0300 ± 200 years Unknown Confirmed 4 Radiocarbon (corrected) Goshiki-dake area, Z-To9 tephra
1600 BCE (?) Unknown Confirmed   Radiocarbon (corrected) Goshiki-dake
2000 BCE ± 500 years Unknown Confirmed   Tephrochronology Goshiki-dake
2300 BCE ± 75 years Unknown Confirmed   Radiocarbon (corrected) Goshiki-dake area, Z-To8 tephra
2600 BCE ± 200 years Unknown Confirmed   Radiocarbon (corrected) Goshiki-dake area, Z-To7 tephra
3350 BCE ± 50 years Unknown Confirmed   Radiocarbon (corrected) Goshiki-dake area, Z-To6 tephra
3850 BCE ± 200 years Unknown Confirmed   Radiocarbon (corrected) Goshiki-dake area, Z-To5 tephra
4150 BCE ± 200 years Unknown Confirmed   Radiocarbon (corrected) Goshiki-dake area, Z-To5b tephra
5500 BCE (?) Unknown Confirmed   Radiocarbon (corrected) Goshiki-dake area
5600 BCE (?) Unknown Confirmed   Radiocarbon (corrected) Goshiki-dake, Z-To5a tephra
7600 BCE (?) Unknown Confirmed   Radiocarbon (corrected) Goshiki-dake area

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.

Photo Gallery


Okama crater of Goryu-dake, the most well-known feature of the Zao volcanic complex, is seen from the east. The 360-m-wide lake is about 60 m deep. The volcanic lake has been the site of many historical eruptions. White mud deposited on the lake floor is periodically disturbed by gas emission, changing the color of the lake water. The Zao volcano group, the most active of northern Honshu, consists of a complex cluster of stratovolcanoes straddling the Pacific Ocean-Japan Sea divide.

Copyrighted photo by Yoshihisa Kawanabe (Japanese Quaternary Volcanoes database, RIODB, http://riodb02.ibase.aist.go.jp/strata/VOL_JP/EN/index.htm and Geol Surv Japan, AIST, http://www.gsj.jp/).
See title for photo information.

Smithsonian Sample Collections Database


There are no samples for Zaozan in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

Affiliated Sites