Hakoneyama

Photo of this volcano
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 35.233°N
  • 139.021°E

  • 1438 m
    4717 ft

  • 283020
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Weekly Report: 18 November-24 November 2015 Citation IconCite this Report


According to a news article from 20 November, JMA lowered the Alert Level for Hakoneyama to 1 (on a scale of 1-5) due to continuing low levels of seismicity.

Source: The Japan Times


Most Recent Bulletin Report: April 1991 (BGVN 16:04) Citation IconCite this Report


Brief earthquake swarm in center of caldera

A swarm of ~300 earthquakes (M <= 2.5) was recorded between 1000 and 1300 on 22 April. Several of the earthquakes, located at 5 km depth in the central part of the caldera, were felt by area residents. Seismicity gradually declined, and had returned to normal by 24 April. No changes in surface activity were observed. Earthquake swarms have been recorded about once a year, including one in August 1990 (M <= 5.1), at the volcano's E foot. Hakone erupted phreatically about 3,000 years ago, and many fumaroles and hot springs remain active.

Information Contacts: JMA.

Weekly Reports - Index


2015: May | June | July | November
2001: August


18 November-24 November 2015 Citation IconCite this Report


According to a news article from 20 November, JMA lowered the Alert Level for Hakoneyama to 1 (on a scale of 1-5) due to continuing low levels of seismicity.

Source: The Japan Times


8 July-14 July 2015 Citation IconCite this Report


On 12 July JMA reported that the webcam continued to record vigorous fumarolic plumes rising from Hakoneyama's Owakudani hot spring area. The Alert Level remained at 3 (on a 5-level scale).

Source: Japan Meteorological Agency (JMA)


1 July-7 July 2015 Citation IconCite this Report


According to a news article a drone that surveyed the Owakudani hot spring district at Hakoneyama recorded damage to three hot spring supply facilities; an exclusion zone for visitors was in effect due to increased seismic activity and an Alert Level raise to 2 (on a 5-level scale) on 6 May. At 1230 on 30 June a small-scale eruption occurred and the Alert Level was raised to 3. On 1 July a news article noted another small-scale eruption (occurring between 0400 and 0500), and JMA reported that ash deposits were visible with the webcam. During fieldwork on 2 July, scientists confirmed new fumaroles at Owakudani that were vigorously emitting white plumes; the new fumaroles had formed during 29-30 June. White fumarolic plumes continued to be emitted through 5 July.

Sources: Japan Meteorological Agency (JMA); The Japan Times; The Japan Times


24 June-30 June 2015 Citation IconCite this Report


JMA reported that on 29 June scientists visiting Hakoneyama observed new fumaroles in a landslide-prone area, appearing after a possible landslide had occurred. Fresh sediment deposits within 2 km were possibly caused by the formation of the fumaroles. Seismicity began increasing at 1930, and a 5-minute-period of volcanic tremor began at 1932. At 1230 on 30 June a small-scale eruption occurred. The Alert Level was raised to 3 (on a 5-level scale).

Source: Japan Meteorological Agency (JMA)


13 May-19 May 2015 Citation IconCite this Report


JMA reported that during 14-17 May seismicity at Hakoneyama remained high. Inclinometer data showed variations related to seismicity, and vigorous steaming from the hot springs was observed. The Alert Level remained at 2 (on a 5-level scale). According to a news article, the ground level in the Owakudani hot spring area had risen 12 cm during 17 April-15 May; the deformation occurred in an area 200 m in diameter. The article also noted that 471 earthquakes were recorded on 15 May, the highest number ever recorded there in one day.

Source: Japan Meteorological Agency (JMA)


6 May-12 May 2015 Citation IconCite this Report


On 6 May JMA raised the Alert Level for Hakoneyama from 1 to 2 (on a 5-level scale). Seismicity had increased on 26 April, and on 5 May three events occurred that were Intensity I. Inclinometer data showed variations related to seismicity, and vigorous steaming from the hot springs was observed. Seismicity remained elevated at least through 10 May.

Source: Japan Meteorological Agency (JMA)


8 August-14 August 2001 Citation IconCite this Report


Elevated seismicity had been recorded at Hakone during June 2001 to at least 8 August. The seismicity was associated with a small amount of inflation that was centered at the volcano. Earthquake hypocenters occurred at depths less than 5 km beneath the volcano. A small swarm was also recorded under the northern end of the Ashino-ko (caldera lake). JMA noted that the change in activity might not be a precursor to an eruption since similar activity has occurred in the past that was not followed by an eruption.

Source: Volcano Research Center-Earthquake Research Institute (University of Tokyo)


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.

04/1991 (BGVN 16:04) Brief earthquake swarm in center of caldera




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


April 1991 (BGVN 16:04) Citation IconCite this Report


Brief earthquake swarm in center of caldera

A swarm of ~300 earthquakes (M <= 2.5) was recorded between 1000 and 1300 on 22 April. Several of the earthquakes, located at 5 km depth in the central part of the caldera, were felt by area residents. Seismicity gradually declined, and had returned to normal by 24 April. No changes in surface activity were observed. Earthquake swarms have been recorded about once a year, including one in August 1990 (M <= 5.1), at the volcano's E foot. Hakone erupted phreatically about 3,000 years ago, and many fumaroles and hot springs remain active.

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
2015 Jun 29 2015 Jul 1 Confirmed   Historical Observations
1170 ± 100 years Unknown Confirmed   Radiocarbon (corrected) Owakudani, Hk-Ow 3-5 tephras
0050 BCE (?) Unknown Confirmed   Tephrochronology NE of Kamiyama, Hk-Ow2 tephra
1050 BCE (?) Unknown Confirmed   Tephrochronology NE of Kamiyama, Hk-Ow1 tephra
1200 BCE (?) Unknown Confirmed 2 Radiocarbon (corrected) NW side of Kami-yama (Kanmuriga-take)
1400 BCE ± 100 years Unknown Confirmed   Radiocarbon (corrected) NW side of Kami-yama (Kanmuriga-take)
3700 BCE ± 100 years Unknown Confirmed 1 Radiocarbon (corrected) Futago-yama
6000 BCE ± 100 years Unknown Confirmed 3 Radiocarbon (corrected) Kami-yama, Hk-Km5 tephra

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


Hakone volcano, seen here from the west, is a broad stratovolcano truncated by two large calderas. A group of dacitic lava domes was constructed in the center of the caldera. The highest dome, Kami-yama, forms the high point of the volcano, topped by the clouds in the center of the photo. The caldera was created during two large Pleistocene eruptions. The latest eruption at Hakone took place about 3000 years ago, although seismic swarms have occurred frequently during the 20th century.

Photo by Lee Siebert, 1977 (Smithsonian Institution).
See title for photo information.
The slopes of a group of post-caldera dacitic lava domes rise at the left above Lake Ashi, which is constrained against the SW rim of Hakone caldera. Lake Ashi was formed when an avalanche from Kami-yama, the highest of the central lava domes, blocked river valleys that drain to the east through a breach in the caldera wall.

Photo by Lee Siebert, 1977 (Smithsonian Institution).
See title for photo information.
Scenic Lake Ashi, seen here from the SE, occupies the SW corner of Hakone caldera. Hakone contains two calderas, the largest of which is 10 x 11 km wide. The arcuate caldera rim is at the left, and the slopes of a group of post-caldera cones form the right-hand shoreline. Post-caldera eruptions have constructed a half dozen lava domes along a SW-NE trend cutting through the center of the calderas. The latest eruption took place about 3000 years ago, although seismic swarms have occurred frequently during the 20th century.

Photo by Lee Siebert, 1963 (Smithsonian Institution).
See title for photo information.
Aerial cable cars stretching across Owakudani provide a view of one of the many thermal areas in Hakone caldera. Hot spring resorts surround a complex of lava domes in the center of Hakone caldera, which is a popular vacation destination SW of Tokyo.

Photo by Lee Siebert, 1963 (Smithsonian Institution).
See title for photo information.
Kamiyama, the highest of a group of lava domes forming the central cone complex of Hakoneyama caldera, rises east of Ashinoko (Lake Ashi). The lake was formed about 3100 years ago when collapse of the NW side of Kamiyama dammed the Hayakawa river valley at the north end of the lake (lower left). Dome and spine extrusion at Kamiyama about 200 radiocarbon-years later marks the last known eruptive activity of Hakone volcano.

Photo by Lee Siebert, 1977 (Smithsonian Institution).
See title for photo information.

Smithsonian Sample Collections Database


The following 54 samples associated with this volcano can be found in the Smithsonian's NMNH Department of Mineral Sciences collections. Catalog number links will open a window with more information.

Catalog Number Sample Description
NMNH 108936 Augite andesite with hypersthene and olivine
NMNH 108937 Dacite
NMNH 108938 Augite andesite
NMNH 108939 Olivine-basalt
NMNH 108942 Andesite pumice with augite and hypersthene
NMNH 108943 Dacitic andesite
NMNH 108944 Hypersthene andesite with augite and olivine
NMNH 108945 Andesite
NMNH 108949 Hypersthene andesite
NMNH 108950 Hypersthene andesite with augite and pigeonite
NMNH 108951 Hypersthene andesite
NMNH 108955 Hypersthene andesite
NMNH 108956 Augite andesite
NMNH 108957 Andesite
NMNH 108958 Hornblende andesite
NMNH 108960 Welded tuff
NMNH 108961 Augite andesite
NMNH 108965 Hypersthene andesite
NMNH 108966 Augite andesite
NMNH 108967 Hypersthene andesite
NMNH 108971 Augite andesite
NMNH 108972 Hypersthene andesite
NMNH 108975 Hypersthene andesite
NMNH 108976 Augite andesite
NMNH 108977 Hypersthene andesite
NMNH 112898 Pigeonite andesite
NMNH 112899 Pyroxene andesite
NMNH 112899 Pyroxene andesite
NMNH 112900 Andesite
NMNH 112900 Andesite
NMNH 112901 Hypersthene andesite
NMNH 112901 Hypersthene andesite
NMNH 112902 Hypersthene andesite
NMNH 112902 Hypersthene andesite
NMNH 112903 Hypersthene dacite
NMNH 112903 Hypersthene dacite
NMNH 112904 Augite andesite with hypersthene and olivine
NMNH 112904 Augite andesite with hypersthene and olivine
NMNH 112904 Augite andesite with hypersthene and olivine
NMNH 112905 Hypersthene andesite
NMNH 112905 Hypersthene andesite
NMNH 113055 "Hypersthene andesite with augite, pigeonite, and others"
NMNH 117801-12 Augite-pigeonite-hypersthene andesite
NMNH 117801-18 Augite andesite with olivine and hypersthene
NMNH 117801-19 Augite andesite with olivine and hypersthene
NMNH 117801-21 Hypersthene-hornblende-quartz dacite
NMNH 117801-25 Olivine andesite
NMNH 117801-27 Obsidian
NMNH 117801-30 Hypersthene-olivine andesite
NMNH 117801-32 Hypersthene dacite
NMNH 117801-35 Pumice
NMNH 117801-4 Augite-hypersthene andesite
NMNH 117801-5 Hornblende-hypersthene andesite
NMNH 117801-6 Andesite

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