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Hachijojima

Photo of this volcano
  • Japan
  • Composite (Stratovolcano(es))
  • 1606 CE
  • Country
  • Landform (Volc Type)
  • Last Known Eruption
  • 33.137°N
  • 139.766°E

  • 854 m
    2802 ft

  • 284050
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Weekly Report: 4 September-10 September 2002 Citation IconCite this Report

In late August, fewer than ten earthquakes occurred at Hachijo-jima per hour and ground deformation had returned to normal levels. On 27 August, very long-period signals were detected near Hachijo-jima. The signals were felt widely on the southern coast of Honshu. The hypocenter of a high-frequency earthquake preceded by a very long-period signal was located NW offshore of the volcano.

Source: Japan Meteorological Agency (JMA) via the Volcano Research Center


Most Recent Bulletin Report: July 2002 (BGVN 27:07) Citation IconCite this Report

Seismic swarms during August 2002

The Japanese Meteorological Agency (JMA) reported that at around 1600 on 13 August 2002 seismic swarms began on Hachijo-jima island (figure 1). The island lies ~300 km S of Tokyo in the Izu island chain. A total of 16 earthquakes were felt by 1700 on 15 August. Hypocenters were located ~2 km off the W shore of the central part of the island, at depths of 5-15 km (according to seismic-wave velocity models) (figure 2). The earthquakes deepened and started migrating to the N, in the direction of Nishi-yama, on the morning on 15 August. Five seismic stations are located on the inhabited island.

Figure (see Caption) Figure 1. Map showing the elongated, NW-SE-trending Hachijo-jima island, consisting of two small Quaternary stratovolcanoes, Higashi-yama to the SE and Nishi-yama to the NW. The small volcanic island of Ko-jima lies several kilometers to the W of Hachijo-jima. Courtesy of Volcano Research Center.
Figure (see Caption) Figure 2. Hypocenters of volcanic earthquakes at Hachijo-jima during 13-15 August 2002 (as of 2000 on 15 August). Sites of seismic stations are shown on figure 13. Courtesy of Shin'ichi Sakai, JMA.

On 16 August JMA reported that high seismicity continued at Hachijo-jima volcano, when volcanic tremor-like waves were recorded. JMA reported that the hourly number of earthquakes had been over 20 since the evening of 13 August; the peak occurred on the morning of 15 August (~250 earthquakes per hour). As of 1500 on 16 August, 22 earthquakes had been felt. Seismic activity began to decrease during the evening of 16 August. JMA reported that during 16-17 August, less than 20 earthquakes occurred per hour. JMA installed two seismometers temporarily on the island on 17 August. JMA released a statement saying that the present seismic activity may continue at the same level for some time without an eruption. The Geographical Survey Institute reported that the GPS station located in the center of the island had migrated 5-6 cm to the E and had been uplifted 10 cm by 1500 on 16 August.

Seismicity around Hachijo-jima decreased by 21 August. Since the afternoon of 20 August, less than 10 earthquakes occurred per hour. Hypocenters had migrated to the NW from the original site of earthquake concentration, advancing parallel to the long axis of the island. Low-frequency earthquakes continued on 21 August; hypocenters were located near the first swarms of 13-15 August.

Information Contacts: Hitoshi Yamasato, Japanese Meteorological Agency (JMA), Volcanological Division, 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan (URL: http://www.jma.go.jp/); Shin'ichi Sakai, Volcano Research Center (VRC), Earthquake Research Institute (ERI), University of Tokyo, 113-0032 1-1-1, Yayoi, Bunkyo-ku, Tokyo (URL: http://www.eri.u-tokyo.ac.jp/VRC/index_E.html); Geographical Survey Institute (GSI), Kitasato 1, Tsukuba Ibaraki, 305-0811 Japan (URL: http://www.gsi.go.jp/).

Weekly Reports - Index


2002: August | September


4 September-10 September 2002 Citation IconCite this Report

In late August, fewer than ten earthquakes occurred at Hachijo-jima per hour and ground deformation had returned to normal levels. On 27 August, very long-period signals were detected near Hachijo-jima. The signals were felt widely on the southern coast of Honshu. The hypocenter of a high-frequency earthquake preceded by a very long-period signal was located NW offshore of the volcano.

Source: Japan Meteorological Agency (JMA) via the Volcano Research Center


21 August-27 August 2002 Citation IconCite this Report

Seismicity that began to increase at Hachijo-jima on 13 August (when 16 earthquakes were recorded) began to decrease on 20 August (less than 10 earthquakes were recorded). The earthquake's hypocenters migrated from NW to SE, roughly parallel to the long axis of the island. Hypocenters of low-frequency earthquakes that occurred on the morning of 21 August were located near the 13-15 August swarm's hypocenters.

Source: Japan Meteorological Agency (JMA) via the Volcano Research Center


14 August-20 August 2002 Citation IconCite this Report

JMA reported that seismicity increased at Hachijo-jima beginning on 13 August around 1600. By 1700 that day 16 earthquakes were felt, with a maximum magnitude of 3. The hypocenters were located ~2 km off of the island's W shore at depths of 5-15 km, depending on assumed seismic-wave velocity models. During the afternoon of the 15th, the earthquakes migrated to the N, without a clear change in depth. By the 16th, volcanic tremor-like waveforms were also recorded. By the evening of the 16th seismicity began to decrease. JMA stated that the overall increase in seismicity might not lead directly to an eruption, though seismicity may continue at a similar level. According to the Geographical Survey Institute, GPS measurements revealed in the center of the island there was 5-6 cm of movement to the E and 10 cm of uplift until about 1500.

Source: Japan Meteorological Agency (JMA) via the Volcano Research Center


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.

07/2002 (BGVN 27:07) Seismic swarms during August 2002




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


July 2002 (BGVN 27:07) Citation IconCite this Report

Seismic swarms during August 2002

The Japanese Meteorological Agency (JMA) reported that at around 1600 on 13 August 2002 seismic swarms began on Hachijo-jima island (figure 1). The island lies ~300 km S of Tokyo in the Izu island chain. A total of 16 earthquakes were felt by 1700 on 15 August. Hypocenters were located ~2 km off the W shore of the central part of the island, at depths of 5-15 km (according to seismic-wave velocity models) (figure 2). The earthquakes deepened and started migrating to the N, in the direction of Nishi-yama, on the morning on 15 August. Five seismic stations are located on the inhabited island.

Figure (see Caption) Figure 1. Map showing the elongated, NW-SE-trending Hachijo-jima island, consisting of two small Quaternary stratovolcanoes, Higashi-yama to the SE and Nishi-yama to the NW. The small volcanic island of Ko-jima lies several kilometers to the W of Hachijo-jima. Courtesy of Volcano Research Center.
Figure (see Caption) Figure 2. Hypocenters of volcanic earthquakes at Hachijo-jima during 13-15 August 2002 (as of 2000 on 15 August). Sites of seismic stations are shown on figure 13. Courtesy of Shin'ichi Sakai, JMA.

On 16 August JMA reported that high seismicity continued at Hachijo-jima volcano, when volcanic tremor-like waves were recorded. JMA reported that the hourly number of earthquakes had been over 20 since the evening of 13 August; the peak occurred on the morning of 15 August (~250 earthquakes per hour). As of 1500 on 16 August, 22 earthquakes had been felt. Seismic activity began to decrease during the evening of 16 August. JMA reported that during 16-17 August, less than 20 earthquakes occurred per hour. JMA installed two seismometers temporarily on the island on 17 August. JMA released a statement saying that the present seismic activity may continue at the same level for some time without an eruption. The Geographical Survey Institute reported that the GPS station located in the center of the island had migrated 5-6 cm to the E and had been uplifted 10 cm by 1500 on 16 August.

Seismicity around Hachijo-jima decreased by 21 August. Since the afternoon of 20 August, less than 10 earthquakes occurred per hour. Hypocenters had migrated to the NW from the original site of earthquake concentration, advancing parallel to the long axis of the island. Low-frequency earthquakes continued on 21 August; hypocenters were located near the first swarms of 13-15 August.

Information Contacts: Hitoshi Yamasato, Japanese Meteorological Agency (JMA), Volcanological Division, 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100, Japan (URL: http://www.jma.go.jp/); Shin'ichi Sakai, Volcano Research Center (VRC), Earthquake Research Institute (ERI), University of Tokyo, 113-0032 1-1-1, Yayoi, Bunkyo-ku, Tokyo (URL: http://www.eri.u-tokyo.ac.jp/VRC/index_E.html); Geographical Survey Institute (GSI), Kitasato 1, Tsukuba Ibaraki, 305-0811 Japan (URL: http://www.gsi.go.jp/).

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.

Eruptive History

There is data available for 18 confirmed Holocene eruptive periods.

[ 1707 ] Uncertain Eruption

Episode 1 | Eruption Episode
1707 - Unknown Evidence from Unknown

List of 2 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion Uncertain
1707    - - - - VEI (Explosivity Index)

1606 Jan 23 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Submarine flank
1606 Jan 23 - Unknown Evidence from Observations: Reported

List of 3 Events for Episode 1 at Submarine flank

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Island ephemeral
1606 Jan 23    - - - - VEI (Explosivity Index)

1605 Oct 27 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Nishi-yama SE flank
1605 Oct 27 - Unknown Evidence from Observations: Reported

List of 4 Events for Episode 1 at Nishi-yama SE flank

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Property Damage
1605 Oct 27    - - - - VEI (Explosivity Index)

1518 Feb - 1523 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Nishi-yama
1518 Feb - 1523 Evidence from Observations: Reported

List of 2 Events for Episode 1 at Nishi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1518 Feb    - - - - VEI (Explosivity Index)

1487 Dec 7 Confirmed Eruption Max VEI: 2

Episode 1 | Eruption Episode Nishi-yama
1487 Dec 7 - Unknown Evidence from Observations: Reported

List of 2 Events for Episode 1 at Nishi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
1487 Dec 7    - - - - VEI (Explosivity Index)

0850 ± 200 years Confirmed Eruption  

Episode 1 | Eruption Episode Nishi-yama summit and SE flank
0850 ± 200 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 3 Events for Episode 1 at Nishi-yama summit and SE flank

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Lava flow
   - - - -    - - - - Ash

0150 BCE ± 50 years Confirmed Eruption  

Episode 1 | Eruption Episode Nishi-yama
0150 BCE ± 50 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 2 Events for Episode 1 at Nishi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash

0350 BCE ± 500 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode NW flank of Higashi-yama
0350 BCE ± 500 years - Unknown Evidence from Correlation: Tephrochronology

List of 4 Events for Episode 1 at NW flank of Higashi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Ash
0350 BCE ± 500 years    - - - - VEI (Explosivity Index)

1150 BCE ± 700 years Confirmed Eruption  

Episode 1 | Eruption Episode SE flank of Nishi-yama (Kanda-yama)
1150 BCE ± 700 years - Unknown Evidence from Correlation: Tephrochronology

List of 3 Events for Episode 1 at SE flank of Nishi-yama (Kanda-yama)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Ash

1250 BCE ± 800 years Confirmed Eruption  

Episode 1 | Eruption Episode Nishi-yama
1250 BCE ± 800 years - Unknown Evidence from Correlation: Tephrochronology

List of 2 Events for Episode 1 at Nishi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash

2050 BCE (?) Confirmed Eruption Max VEI: 5

Episode 1 | Eruption Episode SE of Nishi-yama, NE of Higashi-yama
2050 BCE (?) - Unknown Evidence from Correlation: Tephrochronology

List of 4 Events for Episode 1 at SE of Nishi-yama, NE of Higashi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Pumice
2050 BCE
(?)
   - - - - VEI (Explosivity Index)

2450 BCE ± 500 years Confirmed Eruption Max VEI: 4

Episode 1 | Eruption Episode Nishi-yama
2450 BCE ± 500 years - Unknown Evidence from Correlation: Tephrochronology

List of 5 Events for Episode 1 at Nishi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatomagmatic
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Ash
2450 BCE ± 500 years    - - - - VEI (Explosivity Index)

2550 BCE ± 500 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode S flank of Higashi-yama (Myohoji)
2550 BCE ± 500 years - Unknown Evidence from Correlation: Tephrochronology

List of 3 Events for Episode 1 at S flank of Higashi-yama (Myohoji)

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Pumice
2550 BCE ± 500 years    - - - - VEI (Explosivity Index)

2700 BCE ± 100 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Between Nishi-yama & Higashi-yama
2700 BCE ± 100 years - Unknown Evidence from Isotopic: 14C (calibrated)

List of 4 Events for Episode 1 at Between Nishi-yama & Higashi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatomagmatic
   - - - -    - - - - Pyroclastic flow
2700 BCE ± 100 years    - - - - VEI (Explosivity Index)

3350 BCE ± 1300 years Confirmed Eruption  

Episode 1 | Eruption Episode Nishi-yama
3350 BCE ± 1300 years - Unknown Evidence from Correlation: Tephrochronology

List of 2 Events for Episode 1 at Nishi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Scoria

4650 BCE (?) Confirmed Eruption Max VEI: 5

Episode 1 | Eruption Episode Nishi-yama
4650 BCE (?) - Unknown Evidence from Correlation: Tephrochronology

List of 5 Events for Episode 1 at Nishi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatomagmatic
   - - - -    - - - - Pyroclastic flow
   - - - -    - - - - Ash
4650 BCE
(?)
   - - - - VEI (Explosivity Index)

5020 BCE ± 370 years Confirmed Eruption Max VEI: 3

Episode 1 | Eruption Episode Higashi-yama south flank
5020 BCE ± 370 years - Unknown Evidence from Correlation: Tephrochronology

List of 4 Events for Episode 1 at Higashi-yama south flank

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Phreatic activity
   - - - -    - - - - Lapilli
   - - - -    - - - - Lahar or Mudflow
5020 BCE ± 1000 years    - - - - VEI (Explosivity Index)

7650 BCE ± 3000 years Confirmed Eruption  

Episode 1 | Eruption Episode Nishi-yama
7650 BCE ± 3000 years - Unknown Evidence from Correlation: Tephrochronology

List of 2 Events for Episode 1 at Nishi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Scoria

8020 BCE ± 2640 years Confirmed Eruption Max VEI: 4

Episode 1 | Eruption Episode Nishi-yama
8020 BCE ± 2640 years - Unknown Evidence from Correlation: Tephrochronology

List of 4 Events for Episode 1 at Nishi-yama

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Phreatomagmatic
   - - - -    - - - - Pyroclastic flow
8020 BCE ± 1000 years    - - - - VEI (Explosivity Index)
Deformation History

There is no Deformation History data available for Hachijojima.

Emission History

There is no Emissions History data available for Hachijojima.

GVP Map Holdings

Maps are not currently available due to technical issues.

The maps shown below have been scanned from the GVP map archives and include the volcano on this page. Clicking on the small images will load the full 300 dpi map. Very small-scale maps (such as world maps) are not included.

Smithsonian Sample Collections Database

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

External Sites