Moutohora Island

Photo of this volcano
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 37.858°S
  • 176.98°E

  • 354 m
    1161 ft

  • 241815
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: March 1990 (BGVN 15:03) Citation IconCite this Report


CO2-rich gases from thermal area

The following observations, made by scientists from the USSR and New Zealand during a cruise of the RV Vulkanolog, were reported by W.F. Giggenbach and I. Menyailov.

"...Thermal activity manifests itself largely in areas of hydrothermally altered, steaming ground. The major thermal feature is a vigorously boiling pool near sea level in Sulphur Bay (Ramsay and Hayward, 1971). As indicated by the occurrence of bubble zones (Glasby, 1971), submarine thermal activity extends well SW of the island.

"During both the 1988 and 1990 cruises of the RV Vulkanolog, gas and water samples were collected from the main pool. The waters are essentially acid sulfate (4,000 mg/kg; Cl, 20 mg/kg), steam-heated, initially non-saline groundwater. Compositions of 1988 gases are compared in table 1 with those of 1974 samples from Sulphur Bay spring and the seafloor at 34 m depth (Lyon and others, 1977).

Table 1. Chemical composition of gases collected from vents on and near Whale Island (in mmol/mol of dry gas), March 1974 (Lyon and others, 1977) and during the September 1988 cruise of the RV Vulkanolog.

[Skip text table]
    Vent   Seafloor (34 m depth)    Island (pool)
    Date   10 Sep 74   10 Sep 74    10 Sep 74   10 Mar 88   10 Mar 88

    C          15          15           99           99           99
    CO2       734         680          967          935          937
    H2S        --          --           --         12.5         12.2
    He         --          --           --       0.0028       0.0010
    Ne         --          --           --      0.00004     0.00006
    Ar        1.2         0.8         0.07         0.04         0.03
    H2        0.1         0.3          3.2         11.2          9.7
    O2       14.1         7.5        <0.01        <0.03        <0.03
    N2        131         119           11           13           11
    CH4       120         193           18           28           30

"All gases reflect a hydrothermal origin, and their major component is CO2. The seafloor gases are contaminated with air, probably after sampling. Their higher CH4 and lower H2 contents suggest longer residence at lower temperatures compared to the island samples. The composition of the latter has remained essentially unchanged over the last 14 years."

References. Glasby, G.P., 1971, Direct observation of columnar scattering associated with geothermal gas bubbling in the Bay of Plenty, New Zealand: New Zealand Journal of Marine and Freshwater Research, v. 5, p. 483-496.

Lyon, G.L., Giggenbach, W.F., Singleton, R.J., and Glasby, G.P., 1977, Isotopic and Chemical composition of submarine geothermal gases from the Bay of Plenty, New Zealand: New Zealand Department of Scientific and Industrial Research Bulletin, v. 218, p. 65-67.

Ramsay, W.R.H., and Hayward, B.W., 1971, Geology of Whale Island: Tane, v. 17, p. 9-32.

Information Contacts: I. Menyailov and A. Ivanenko, IV, Petropavlovsk; W. Giggenbach, DSIR Chemistry, Petone.

The Global Volcanism Program has no Weekly Reports available for Moutohora Island.

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.

03/1990 (BGVN 15:03) CO2-rich gases from thermal area




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


March 1990 (BGVN 15:03) Citation IconCite this Report


CO2-rich gases from thermal area

The following observations, made by scientists from the USSR and New Zealand during a cruise of the RV Vulkanolog, were reported by W.F. Giggenbach and I. Menyailov.

"...Thermal activity manifests itself largely in areas of hydrothermally altered, steaming ground. The major thermal feature is a vigorously boiling pool near sea level in Sulphur Bay (Ramsay and Hayward, 1971). As indicated by the occurrence of bubble zones (Glasby, 1971), submarine thermal activity extends well SW of the island.

"During both the 1988 and 1990 cruises of the RV Vulkanolog, gas and water samples were collected from the main pool. The waters are essentially acid sulfate (4,000 mg/kg; Cl, 20 mg/kg), steam-heated, initially non-saline groundwater. Compositions of 1988 gases are compared in table 1 with those of 1974 samples from Sulphur Bay spring and the seafloor at 34 m depth (Lyon and others, 1977).

Table 1. Chemical composition of gases collected from vents on and near Whale Island (in mmol/mol of dry gas), March 1974 (Lyon and others, 1977) and during the September 1988 cruise of the RV Vulkanolog.

[Skip text table]
    Vent   Seafloor (34 m depth)    Island (pool)
    Date   10 Sep 74   10 Sep 74    10 Sep 74   10 Mar 88   10 Mar 88

    C          15          15           99           99           99
    CO2       734         680          967          935          937
    H2S        --          --           --         12.5         12.2
    He         --          --           --       0.0028       0.0010
    Ne         --          --           --      0.00004     0.00006
    Ar        1.2         0.8         0.07         0.04         0.03
    H2        0.1         0.3          3.2         11.2          9.7
    O2       14.1         7.5        <0.01        <0.03        <0.03
    N2        131         119           11           13           11
    CH4       120         193           18           28           30

"All gases reflect a hydrothermal origin, and their major component is CO2. The seafloor gases are contaminated with air, probably after sampling. Their higher CH4 and lower H2 contents suggest longer residence at lower temperatures compared to the island samples. The composition of the latter has remained essentially unchanged over the last 14 years."

References. Glasby, G.P., 1971, Direct observation of columnar scattering associated with geothermal gas bubbling in the Bay of Plenty, New Zealand: New Zealand Journal of Marine and Freshwater Research, v. 5, p. 483-496.

Lyon, G.L., Giggenbach, W.F., Singleton, R.J., and Glasby, G.P., 1977, Isotopic and Chemical composition of submarine geothermal gases from the Bay of Plenty, New Zealand: New Zealand Department of Scientific and Industrial Research Bulletin, v. 218, p. 65-67.

Ramsay, W.R.H., and Hayward, B.W., 1971, Geology of Whale Island: Tane, v. 17, p. 9-32.

Information Contacts: I. Menyailov and A. Ivanenko, IV, Petropavlovsk; W. Giggenbach, DSIR Chemistry, Petone.

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

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


Moutohora (Whale) Island is the elongated island 11 km offshore from the city of Whakatane at the mouth of the Whakatane River in the center of this Landsat image. The 354-m-high central dome complex on the 15 x 5 km wide island is flanked by two lava domes, Pa Hill Dome (also known as West Dome) at the NW tip of the island and East Dome at the opposite end. Eruptive activity ceased during the Pleistocene, but thermal activity continues. Rurima Rocks and Moutoko Island lie WNW, and the large bay at the lower right is Ohiwa Harbour.

NASA Landsat image, 2000 (courtesy of Hawaii Synergy Project, Univ. of Hawaii Institute of Geophysics & Planetology).
See title for photo information.

Smithsonian Sample Collections Database


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

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