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Kaitoku Seamount

No photo available for this volcano
  • Japan
  • Submarine
  • 1984 CE
  •  
  • Country
  • Primary Volcano Type
  • Last Known Eruption
  •  
  • 26.127°N
  • 141.102°E

  • -95 m
    -312 ft

  • 284100
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number
Most Recent Weekly Report: 25 January-31 January 2023 Citation IconCite this Report

Discolored water around the Kaitoku Seamount was visible in a 26 January Sentinel 2 satellite image. The plume was diffuse and dispersed a few kilometers E. No discolored water was visible in a 31 January image.

Source: Sentinel Hub


Most Recent Bulletin Report: December 1990 (BGVN 15:12) Citation IconCite this Report

No water discoloration seen in 1990

No discolorations were observed at . . . Kaitoku . . . during 1990.

Information Contacts: Hydrographic Department, JMSA.

Weekly Reports - Index


2023: January
2022: August | December


25 January-31 January 2023 Citation IconCite this Report

Discolored water around the Kaitoku Seamount was visible in a 26 January Sentinel 2 satellite image. The plume was diffuse and dispersed a few kilometers E. No discolored water was visible in a 31 January image.

Source: Sentinel Hub


4 January-10 January 2023 Citation IconCite this Report

Discolored water around the Kaitoku Seamount was visible in 1 and 6 January Sentinel satellite images. Concentric circles of discolored water radiated out from the vent area and a plume drifted W. The plume of discolored water extended S in the 6 January image.

Source: Sentinel Hub


21 December-27 December 2022 Citation IconCite this Report

After JMA first reported new activity around the Kaitoku Seamount in August, discolored water continued to be periodically visible in Sentinel satellite images through 27 December. Though weather clouds sometimes prevented views of the vent area, and on occasion no activity was visible in clear images, plumes of discolored water drifting away from the vent area appeared to become more frequent in October. Images from 18 October, and 22 and 27 November possibly captured material at the surface or an eruption plume rising above the water. The Japan Coast Guard posted pictures of disturbed water around the vent in November. Recent Sentinel images on 17 and 27 December captured plumes of discolored water drifting as far as 10 km from the vent area.

Sources: Sentinel Hub; Japan Coast Guard


17 August-23 August 2022 Citation IconCite this Report

JMA reported that discolored water around the Kaitoku Seamount was visible during 18-19 August.

Sources: Japan Meteorological Agency (JMA); Japan Coast Guard


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.

02/1984 (SEAN 09:02) Large area of discolored water; small plumes

04/1984 (SEAN 09:04) Acoustic waves recorded in French Polynesia

05/1984 (SEAN 09:05) Discolored water; floating lapilli; formal name

10/1984 (SEAN 09:10) Discolored water after 3 months of quiet

12/1990 (BGVN 15:12) No water discoloration seen in 1990




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


February 1984 (SEAN 09:02) Citation IconCite this Report

Large area of discolored water; small plumes

On 7 March at 1230, the crew of a Japan Maritime Self-Defense Force (JMSDF) transport plane flying about 130 km N of Iwo-Jima observed a fan-shaped zone of discolored sea water that extended about [28] km WSW from a submarine vent. The maximum width of the discolored zone was about 9 km. A helicopter flew over the area shortly thereafter and its crew estimated that the extent of the reddish-brown water was roughly as large as Iwo Jima Island (about 5 x 8 km).

The next morning, JMSA personnel observed continuous submarine eruptive activity. Gray or yellowish brown water was ejected every 10 minutes and waves spread outward from the vents. The sea colors included gray, white, yellowish brown, and reddish brown. JMSA observers saw neither plumes nor floating ejecta, although small white plumes and rocks or reefs were seen during a flight by the JMSDF at about noon the same day. On 12 March, personnel aboard a JMSDF patrol plane again saw floating material, and a plume about 100 m above sea level. Only discoloration was found during a JMSA flight 13 March. As of the 13th, no new island had been observed at the eruption site.

The activity was located near the site of an eruption reported in 1543 at 26.00°N, 140.77°E.

Information Contacts: JMA.


April 1984 (SEAN 09:04) Citation IconCite this Report

Acoustic waves recorded in French Polynesia

RSP stations on Rangiroa, Tubuai, and Rikitéa recorded acoustic waves (T-phase) from a strong submarine volcanic eruption in the vicinity of the Izu Islands. Between 25 March and 30 April, more than 500 signals were received, 300 between 2 and 9 April. Most of the events were impulsive and of short duration, indicating explosive volcanic activity at a shallow depth. Some of the events were emergent and of longer duration indicating quiet emission of lava. J.M. Talandier noted that these events appear to be correlated with the submarine activity reported in 9:2.

Information Contacts: J. Talandier, Lab. de Géophysique, Tahiti.


May 1984 (SEAN 09:05) Citation IconCite this Report

Discolored water; floating lapilli; formal name

JMSA observations beginning 7 March indicated that eruptive activity was at its highest level in mid to late March, when floating ejecta and vapor plumes were nearly always seen. Beginning in April, activity subsided gradually. The area of discolored water decreased from 13 x 30 km in early March to 300 m in diameter in early May (table 1).

On either side of the submarine vent are two shallow areas, at 26.13°N, 141.10°E, and 26.05°N, 140.93°E (figure 1). JMSA has formally named the feature Kaitoku Kaizan (Kaitoku Seamount).

Figure (see Caption) Figure 1. Cross-section (top) and bathymetry (bottom) at Kaitoku Seamount. Courtesy of JMSA.

Information Contacts: JMA, Tokyo.


October 1984 (SEAN 09:10) Citation IconCite this Report

Discolored water after 3 months of quiet

JMSA reconnaissance revealed few signs of activity since the March eruption. Pumice was observed only around the eruption site; none washed up on shore.

Activity gradually declined. To the crew that overflew the area at noon on 9 April, the water discoloration was barely distinguishable, and no ejecta or plume was seen (table 1). JMSA and JMSDF saw no discolored water or other activity on 10 and 31 July, 1 August, and 6 and 26 September. However, the crew of the MV Emblem reported a 3.5-5-km area of upwelling and water discoloration on 15 October.

Table 1. JMSA observations at Kaitoku Seamount, March-June 1984. Courtesy of JMA.

Date Observation
07 Mar 1984 9 x [28] km of discolored water
08 Mar 1984 Floating lapilli; 0.5-3 x 50 km of discolored water
09 Mar 1984 Seawater temperature at vent 0.5°C higher than floating lapilli; 9-13 x 30 km of discolored water
12 Mar 1984 Floating lapilli; discolored water
13 Mar 1984 Seawater near vent 0.5-1°C higher; floating lapilli; vapor plume
15 Mar 1984 Floating lapilli
16-19 Mar 1984 Floating lapilli; vapor plume
22 Mar 1984 Dark plume; luminescence at night
23 Mar 1984 Vapor plume; luminescence at night
24-25 Mar 1984 Vapor plume
26 Mar 1984 Floating lapilli
09 Apr 1984 0.3 x 5 km of very weak water discoloration
09-10 May 1984 Area of discolored water 0.3 km in diameter
15 May 1984 White upwelling and discoloration, 3.5 km in diameter
18 May 1984 Milky white discoloration, 0.18 km wide
09 Jun 1984 Weak green discoloration, 0.15 x 0.05 km

Further Reference. Tsuchide, M., Kato, S., Uchida, A., Sato, H., Konishi, N., Osaka, J., and Hirabayashi, J., 1985, Submarine volcanic activity at the Kaitoku seamount in 1984: Rep. Hydrograph. Res., v. 20, p. 47-82.

Information Contacts: JMA, Tokyo.


December 1990 (BGVN 15:12) Citation IconCite this Report

No water discoloration seen in 1990

No discolorations were observed at . . . Kaitoku . . . during 1990.

Information Contacts: Hydrographic Department, JMSA.

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 3 confirmed Holocene eruptive periods.

2022 Aug 18 - 2023 Jan 26 Confirmed Eruption  

Episode 1 | Uncertain Episode
2022 Aug 18 - 2023 Jan 26 Evidence from Observations: Reported
 Discolored water around the Kaitoku Seamount was visible during 18-19 August 2022.

List of 1 Events for Episode 1

Start Date End Date Event Type Event Remarks
2022 Aug 18 2022 Aug 19 Observation Discolored seawater.

[ 1986 Jun 18 - 1986 Jun 18 ] Uncertain Eruption

[ 1984 Dec 23 - 1984 Dec 23 ] Uncertain Eruption

1984 Mar 8 - 1984 Mar 26 (?) Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode Higashi-Kaitokuba
1984 Mar 8 - 1984 Mar 26 (?) Evidence from Observations: Reported

List of 2 Events for Episode 1 at Higashi-Kaitokuba

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Pumice
1984 Mar 8    - - - - VEI (Explosivity Index)

1543 Confirmed Eruption Max VEI: 0

Episode 1 | Eruption Episode West flank of Nishi-Kaitokuba
1543 - Unknown Evidence from Observations: Reported

List of 1 Events for Episode 1 at West flank of Nishi-Kaitokuba

Start Date End Date Event Type Event Remarks
1543    - - - - VEI (Explosivity Index)
Deformation History

There is no Deformation History data available for Kaitoku Seamount.

Emission History

There is no Emissions History data available for Kaitoku Seamount.

Photo Gallery

The Global Volcanism Program has no photographs available for Kaitoku Seamount.

GVP Map Holdings

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. The maps database originated over 30 years ago, but was only recently updated and connected to our main database. We welcome users to tell us if they see incorrect information or other problems with the maps; please use the Contact GVP link at the bottom of the page to send us email.


Title: Geol Map of Japan/ Geol Atlas
Publisher: Geol Survey of Japan
Country: Japan
Year: 1982
Map Type: Geology
Scale: 1:1,000,000
Map of Geol Map of Japan/ Geol Atlas

Title: Geological Map of Japan
Publisher: Geological Survey of Japan
Country: Japan
Year: 1978
Map Type: Geology
Scale: 1:1,000,000
Map of Geological Map of Japan

Title: Ogasawara-Gunto
Publisher: US Army Map Service
Country: Japan
Year: 1944
Series: AMS
Map Type: Topographic
Scale: 1:1,000,000
Map of Ogasawara-Gunto
Smithsonian Sample Collections Database

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

External Sites