Eastern Gemini Seamount

No photo available for this volcano
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 20.98°S
  • 170.28°E

  • -80 m
    -262 ft

  • 258001
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: February 1996 (BGVN 21:02) Citation IconCite this Report


Submarine eruption; the first recorded historical activity

A submarine eruption was observed in the southern New Hebrides island arc (Vanuatu), an area without previously documented historical activity. The activity was first observed by the merchant ship OSCO STAR cruising in this area on 18 February around 1800. It was described as "continual steam and frequent vertical bursts of very dark water." Observations during a New Caledonia Coast Guard flight on 19 February revealed a white zone within a steaming black patch. A similar flight on 22 February enabled a television crew from RFO New Caledonia to take videotape footage for the local news. Observers on that flight noted that the white zone, from which steam was rising, had a diameter of ~400 m. This zone was located inside a wider ellipse, brown-ochre in color, elongated ~4 km down-current. Every 3-9 minutes an explosion sent black products ~20 m above sea level. After each explosion, the diameter of the white area diminished drastically, rising again during the next explosion. The black products were diluted to form the brown-ochre zone. This activity was probably similar to that documented on 18 February.

Located ~100 km S of Anatom Island, about halfway between Yasur Volcano (Tanna Island) and Matthew Island, the Eastern Gemini seamount is one of several seamounts along the southern submarine extension of the New Hebrides island arc. Several basalt samples and one andesite dredged from this seamount in 1989 (Monzier and others, 1993) were described as glassy, vesicular, and extremely fresh (Bargibant and others, 1989). Because all of the samples were devoid of marine animal traces, the activity was described as very recent. The nearby Western Gemini seamount is located near 21.0°S, 170.05°E, at a depth of 30 m below sea level. Well-developed marine life around its summit suggests that its activity is older.

References. Monzier, M., Danyushevsky, L.V., Crawford, A.J., Bellon, H., and Cotten, J., 1993, High-Mg andesites from the southern termination of the New Hebrides island arc (SW Pacific): Journal of Volcanology and Geothermal Research, v. 57, p. 193-217.

Bargibant and others, 1989, ORSTOM Noumea Earth Sciences Report, no. 12, 13 p. (unpublished).

Information Contacts: Bernard Pelletier, Centre ORSTOM de Noumea, BP A5, Noumea, New Caledonia (Email: pelletib@noumea.orstom.nc); Michel Lardy, ORSTOM, BP 76, Port Vila, Vanuatu (Email: lardy@vanuatu.orstom.nc); Michel Monzier and Claude Robin, ORSTOM, AP 17-11-6596 CCI, Quito, Ecuador (Email: monzier@orstom.ecx.ec, robin@orstom.ecx.ec); Jean-Philippe Eissen, Centre ORSTOM de Brest, BP 70, 29280 Plouzane, France (Email: eissen@orstom.fr).

The Global Volcanism Program has no Weekly Reports available for Eastern Gemini 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.

02/1996 (BGVN 21:02) Submarine eruption; the first recorded historical activity




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


February 1996 (BGVN 21:02) Citation IconCite this Report


Submarine eruption; the first recorded historical activity

A submarine eruption was observed in the southern New Hebrides island arc (Vanuatu), an area without previously documented historical activity. The activity was first observed by the merchant ship OSCO STAR cruising in this area on 18 February around 1800. It was described as "continual steam and frequent vertical bursts of very dark water." Observations during a New Caledonia Coast Guard flight on 19 February revealed a white zone within a steaming black patch. A similar flight on 22 February enabled a television crew from RFO New Caledonia to take videotape footage for the local news. Observers on that flight noted that the white zone, from which steam was rising, had a diameter of ~400 m. This zone was located inside a wider ellipse, brown-ochre in color, elongated ~4 km down-current. Every 3-9 minutes an explosion sent black products ~20 m above sea level. After each explosion, the diameter of the white area diminished drastically, rising again during the next explosion. The black products were diluted to form the brown-ochre zone. This activity was probably similar to that documented on 18 February.

Located ~100 km S of Anatom Island, about halfway between Yasur Volcano (Tanna Island) and Matthew Island, the Eastern Gemini seamount is one of several seamounts along the southern submarine extension of the New Hebrides island arc. Several basalt samples and one andesite dredged from this seamount in 1989 (Monzier and others, 1993) were described as glassy, vesicular, and extremely fresh (Bargibant and others, 1989). Because all of the samples were devoid of marine animal traces, the activity was described as very recent. The nearby Western Gemini seamount is located near 21.0°S, 170.05°E, at a depth of 30 m below sea level. Well-developed marine life around its summit suggests that its activity is older.

References. Monzier, M., Danyushevsky, L.V., Crawford, A.J., Bellon, H., and Cotten, J., 1993, High-Mg andesites from the southern termination of the New Hebrides island arc (SW Pacific): Journal of Volcanology and Geothermal Research, v. 57, p. 193-217.

Bargibant and others, 1989, ORSTOM Noumea Earth Sciences Report, no. 12, 13 p. (unpublished).

Information Contacts: Bernard Pelletier, Centre ORSTOM de Noumea, BP A5, Noumea, New Caledonia (Email: pelletib@noumea.orstom.nc); Michel Lardy, ORSTOM, BP 76, Port Vila, Vanuatu (Email: lardy@vanuatu.orstom.nc); Michel Monzier and Claude Robin, ORSTOM, AP 17-11-6596 CCI, Quito, Ecuador (Email: monzier@orstom.ecx.ec, robin@orstom.ecx.ec); Jean-Philippe Eissen, Centre ORSTOM de Brest, BP 70, 29280 Plouzane, France (Email: eissen@orstom.fr).

Eruptive History


Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).


Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1996 Feb 18 1996 Feb 22 (in or after) Confirmed 1 Historical Observations

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.

The Global Volcanism Program has no photographs available for Eastern Gemini Seamount.

Smithsonian Sample Collections Database


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

Affiliated Sites