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Mikura Seamount

No photo available for this volcano
  • Japan
  • Japan, Taiwan, Marianas
  • Submarine
  • Pleistocene
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 33.725°N
  • 139.408°E

  • -321 m
    -1053 ft

  • 284043
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: October 1990 (BGVN 15:10) Citation IconCite this Report

Three bursts of seismicity near Mikura Seamount

A swarm of earthquakes began at 0624 on 5 October 1990, in the sea ~20 km SW of Mikura-jima Island (figure 3). A second burst occurred 13 October, following a gradual decline from the 5th, and a third burst occurred on 21 October (figure 4). A total of about 30 shocks were felt by residents on Mikura-jima and nine were felt on Miyake-jima Island (at Miyake-jima Weather Station), ~40 km NNE of the epicentral area. The largest event was M 4.3 and occurred on 27 October. Depths of most of the located events ranged from 20 to 30 km, although depth control was poor.

Figure (see Caption) Figure 3. Epicentral distribution of earthquakes (M >= 3.0) off Mikura-jima, October 1990. Courtesy of JMA.
Figure (see Caption) Figure 4. Daily number of located earthquakes off Mikura-jima, October 1990. Courtesy of JMA.

The swarm occurred in the vicinity of Mikura Seamount, a cone-shaped feature with a summit ~300 m below sea level and 1,400 m above the surrounding sea floor. No surface phenomena were reported in the area in October, nor have any been reported in historical time. The last swarm near this site took place in December 1982, and was more vigorous, including one M 6.4 event.

Information Contacts: JMA.

The Global Volcanism Program has no Weekly Reports available for Mikura Seamount.

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.

12/1982 (BGVN 07:12) Earthquake sequence not volcanic

10/1990 (BGVN 15:10) Three bursts of seismicity near Mikura Seamount




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


December 1982 (BGVN 07:12) Citation IconCite this Report

Earthquake sequence not volcanic

Beginning 27 December there have been many recorded earthquakes with epicenters in the ocean about 40 km S of Miyake-jima Island (~200 km S of Tokyo; figures 1 and 2). The first felt shock occurred at 1533. At 1537 on 28 December the largest, magnitude [6.4] on the JMA scale, originated at the N edge of the epicentral area. It was followed by gradually decreasing aftershock activity. Earthquake swarms or main shock-aftershock events in the sea around Miyake-jima occurred in July and September 1980, and . . . March 1981. The USGS/NEIS recorded four shocks of magnitude 5 or greater (table 1).

Figure (see Caption) Figure 1. Epicenters of earthquakes larger than magnitude 3, 27-31 December 1982. The epicentral area is 40 km S of Miyake-jima Island. The largest open circle is the main shock that occurred 28 December at 1537, 30 km S of Miyake-jima. Focal depths ranged from 0-20 km. The January 1983 earthquakes were located in the same area. Courtesy of JMA.
Figure (see Caption) Figure 2. Hourly and daily (inset) number of earthquakes in the Izu Islands recorded at Miyake-jima Weather Station, 27 December 1982-4 January 1983. Courtesy of JMA.

Table 1. Earthquakes of Ms >= 5 on 28 December 1982 in the Izu Islands, Japan. Courtesy of the USGS.

Time Magnitude Latitude Longitude Focal Depth
1024 5.0 33.74°N 139.46°E shallow
1053 5.5 33.70°N 139.44°E shallow
1112 5.1 33.70°N 139.52°E shallow
1537 6.1 33.77°N 139.51°E 20 km

Personnel from the Miyake-jima Weather Station visited the summit area (Oyama) on 29 December, but observed no unusual phenomena. The events were interpreted as having been too far from Miyake-jima to be precursors of volcanic activity. A group of shallow earthquakes occurred close to Miyake-jima a few months before the last eruption in 1962.

Information Contacts: JMA, Tokyo; USGS/NEIS, Denver CO, USA


October 1990 (BGVN 15:10) Citation IconCite this Report

Three bursts of seismicity near Mikura Seamount

A swarm of earthquakes began at 0624 on 5 October 1990, in the sea ~20 km SW of Mikura-jima Island (figure 3). A second burst occurred 13 October, following a gradual decline from the 5th, and a third burst occurred on 21 October (figure 4). A total of about 30 shocks were felt by residents on Mikura-jima and nine were felt on Miyake-jima Island (at Miyake-jima Weather Station), ~40 km NNE of the epicentral area. The largest event was M 4.3 and occurred on 27 October. Depths of most of the located events ranged from 20 to 30 km, although depth control was poor.

Figure (see Caption) Figure 3. Epicentral distribution of earthquakes (M >= 3.0) off Mikura-jima, October 1990. Courtesy of JMA.
Figure (see Caption) Figure 4. Daily number of located earthquakes off Mikura-jima, October 1990. Courtesy of JMA.

The swarm occurred in the vicinity of Mikura Seamount, a cone-shaped feature with a summit ~300 m below sea level and 1,400 m above the surrounding sea floor. No surface phenomena were reported in the area in October, nor have any been reported in historical time. The last swarm near this site took place in December 1982, and was more vigorous, including one M 6.4 event.

Information Contacts: JMA.

The Global Volcanism Program has no synonyms or subfeatures listed for Mikura Seamount.

Eruptive History

The Global Volcanism Program is not aware of any Holocene eruptions from Mikura Seamount. If this volcano has had large eruptions (VEI >= 4) prior to 10,000 years ago, information might be found on the Mikura Seamount page in the LaMEVE (Large Magnitude Explosive Volcanic Eruptions) database, a part of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).

Deformation History

There is no Deformation History data available for Mikura Seamount.

Emission History

There is no Emissions History data available for Mikura Seamount.

Photo Gallery

The Global Volcanism Program has no photographs available for Mikura 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: Computer Generated Geologic Map of Japan
Publisher: Geological Survey of Japan
Country: Japan
Year: 1990
Series: No 22
Map Type: Geology
Scale: 1:2,000,000
Map of Computer Generated Geologic Map of Japan
Title: Japan, South Korea
Publisher: DMA Aerospace Center
Country: Japan, S Korea
Year: 1988
Series: ONC
Map Type: Topographic
Scale: 1:1,000,000
Map of Japan, South Korea
Title: (B) Q Maps of Japan Landforms, Geol, Tect: Central
Publisher: Univ of Tokyo Press & Japan Association for Quaternary Research
Country: Japan
Year: 1987
Map Type: Geology
Scale: 1:1,000,000
Map of (B) Q Maps of Japan Landforms, Geol, Tect: Central
Publisher: Soviet Ministry
Country: USSR
Year: 1984
Series: B1754
Map Type: Topographic
Scale: 1:2,500,000
Map of
Title: Historical Japan
Publisher: National Geographic Society
Country: Japan
Year: 1984
Series: National Geographic
Map Type: Geographic
Scale: 1:2,982,000
Map of Historical Japan
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: Central Japan
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1980
Series: CIM 1:1 mil
Map Type: Topographic
Scale: 1:1,000,000
Map of Central Japan
Title: The Southwest of Miyake Sima
Publisher: Maritime Safety Agency
Country: Japan
Year: 1980
Map Type: Bathymetric
Scale: 1:200,000
Map of The Southwest of Miyake Sima
Title: Central Japan
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1980
Map Type: Topographic
Scale: 1:1,000,000
Map of Central Japan
Title: Central Japan
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1980
Map Type: Topographic
Scale: 1:1,000,000
Map of Central Japan
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: 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: Distribution Map of Hot Springs in Japan
Publisher: Geological Survey of Japan
Country: Japan
Year: 1975
Series: 1:2,000,000
Map Type: Unknown
Scale: 1:2,000,000
Map of Distribution Map of Hot Springs in Japan
Title: (Japanese) Geol map of Japan
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1974
Series: from Natl Atlas Japan
Map Type: Geology
Scale: 1:2,500,000
Map of (Japanese) Geol map of Japan
Title: Landform Classification
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1972
Series: from Natl Atlas Japan
Map Type: Unknown (Land)
Scale: 1:2,500,000
Map of Landform Classification
Title: Land Use
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1972
Series: from Natl Atlas Japan
Map Type: Unknown (Land)
Scale: 1:2,500,000
Map of Land Use
Title: Population Distribution
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1972
Series: from Natl Atlas Japan
Map Type: Unknown
Scale: 1:2,500,000
Map of Population Distribution
Title: River Systems
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1972
Series: from Natl Atlas Japan
Map Type: Unknown
Scale: 1:2,500,000
Map of River Systems
Title: Central Japan
Publisher: Geographical Survey Institute of Japan
Country: Japan
Year: 1966
Map Type: Topographic
Scale: 1:1,000,000
Map of Central Japan
Title: Hachijo-Jima
Publisher: US Army Map Service
Country: Japan
Year: 1954
Series: AMS
Map Type: Topographic
Scale: 1:250,000
Map of Hachijo-Jima
Title: Shizuoka
Publisher: US Army Map Service
Country: Japan
Year: 1945
Series: AMS
Map Type: Topographic
Scale: 1:250,000
Map of Shizuoka
Title: O-Shima
Publisher: US Army Map Service
Country: Japan
Year: 1945
Series: AMS
Map Type: Topographic
Scale: 1:250,000
Map of O-Shima
Title: Tokyo
Publisher: US Army Map Service
Country: Japan
Year: 1943
Series: AMS
Map Type: Topographic
Scale: 1:1,000,000
Map of Tokyo
Smithsonian Sample Collections Database

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

Affiliated Sites