Unnamed

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 20.85°S
  • 175.53°W

  • -13 m
    -43 ft

  • 243030
  • Latitude
  • Longitude

  • Summit
    Elevation

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    Number

Most Recent Bulletin Report: March 1993 (BGVN 24:03)


Eruption NW of Tongatapu builds temporary island in January

This volcanic center in the Tonga Islands, 35 km NW of Tongatapu (figure 1) and S of Falcon Island, forms part of the Tofua Volcanic Arc (TVA). The following report was compiled from various sources, as well as a submission from Paul Taylor based in part on information obtained from Tongan colleagues.

Figure 1. Location map of the southern part of the central region of the Tonga Platform and Tofua Volcanic Arc showing the site of the January 1999 volcanic activity in Tonga. Note the NNE-SSW trending trough-like feature that separates the volcanic arc and the Tonga Platform in this region, which may be a southerly extension of the Tofua Trough. Falcon Island is north of the January 1999 eruption site; the structure SSE of Falcon Island contains the islands of Hunga Ha'apai and Hunga Tonga, and was the site of submarine eruptions in 1912, 1937, and 1988. Bathymetric contours are at intervals of 500 m. Courtesy of Paul Taylor.

The Tonga Chronicle noted that the activity was first reported to Tonga Defense Services on 8 January by Carl Riechelmann, who had seen a plume coming from the site. On 12 January 1999 the Tonga Defence Services flew a photographic mission to record the reported appearance of a new island. Shortly after departing Tongatapu's Fua'amoto Airport in a Twin Beech equipped for surveillance operations, the crew sighted billowing white plumes from the volcano. The aircraft approached cautiously at 300 m altitude, made one circuit, then descended to 150 m for closer observation. The plane circled for almost an hour while a series of still photographs, as well as a video, were taken. During this time the crew noted that the island appeared to exhibit a pattern of rising, then receding. The island was estimated to be roughly 200-300 m long and 30-40 m wide. The crew also saw lava in a small vent that appeared to be located within a 100-m cone. The island was located at 20° 51.55'S, 175° 32.47'W (20.86°S, 175.54°W). Photographs and a report of their observations were posted on the website of Tonga Cable and Wireless.

Submarine activity continued on 14 January, with turbulent water present around a 40 x 300 m shoal, but no island was observed. Reports described a vent producing an ash-and-steam column and ejecting lava fragments, and floating pumice near the eruption site.

A precautionary Notice to Airmen (NOTAM) was issued to aviators on 14 January by the Nadi Aviation Control Center declaring an area within 5.5 km of the eruption site a danger area. Pilots were requested to report any signs of volcanic activity. Tongan officials also issued a warning to shipping transiting the area.

On 15 January a survey team, including two geologists from the Ministry of Land, Survey, and Natural Resources, inspected the island from the deck of the VOEA Savea, according to a report in the Tonga Chronicle. At that time the island had disappeared beneath the ocean surface, but the site was still emitting smoke and fumes. Because of possible danger, boats were warned to stay away.

Information Contacts: Paul W. Taylor, Australian Volcanological Investigations, PO Box 291, Pymble, NSW 2073, Australia (Email: avitaylor@peg.apc.org); Kelepi Mafi, Ministry of Lands, Survey, and Natural Resources, P.O. Box 5, Nuku'Alofa, Kingdom of Tonga; Tonga Cable and Wireless, Private Bag 4, Nuku'alofa, Kingdom of Tonga (URL: http://www.candw.to/); Tonga Chronicle, PO Box 197, Nuku'alofa, Kingdom of Tonga (URL: www.netstorage.com/kami/tonga/news); Tom Fox, International Civil Aviation Organization, 999 University Street, Montreal, Quebec H3C 5H7, Canada; Brad Scott, Wairakei Research Centre, Institute of Geological and Nuclear Sciences (IGNS) Limited, Private Bag 2000, Wairakei, New Zealand (URL: http://www.gns.cri.nz/, Email: bscott@gns.cri.nz).

The Global Volcanism Program has no Weekly Reports available for Unnamed.

Index of Bulletin Reports


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.

00/1974 (Ref 1984) No activity as of 1974

03/1993 (BGVN 24:03) Eruption NW of Tongatapu builds temporary island in January




Bulletin Reports

All information contained in these reports is preliminary and subject to change.


00/1974 (Ref 1984) No activity as of 1974

Admiralty sailing directions (Hydrographer of the Royal Navy, 1984) reported volcanic activity at 20.85°S, 175.55°W in 1970, the site of 1911 and 1923 activity, but noted that in 1974 the volcano was dormant. This entry suggests that the Navy received a report of activity from a passing ship.

Reference. Hydrographer of the Royal Navy, 1984, West approaches - off-lying danger: Pacific Islands Pilot, v. II, British Admiralty Bureau, London, UK, p. 330.

Information Contacts:

03/1993 (BGVN 24:03) Eruption NW of Tongatapu builds temporary island in January

This volcanic center in the Tonga Islands, 35 km NW of Tongatapu (figure 1) and S of Falcon Island, forms part of the Tofua Volcanic Arc (TVA). The following report was compiled from various sources, as well as a submission from Paul Taylor based in part on information obtained from Tongan colleagues.

Figure 1. Location map of the southern part of the central region of the Tonga Platform and Tofua Volcanic Arc showing the site of the January 1999 volcanic activity in Tonga. Note the NNE-SSW trending trough-like feature that separates the volcanic arc and the Tonga Platform in this region, which may be a southerly extension of the Tofua Trough. Falcon Island is north of the January 1999 eruption site; the structure SSE of Falcon Island contains the islands of Hunga Ha'apai and Hunga Tonga, and was the site of submarine eruptions in 1912, 1937, and 1988. Bathymetric contours are at intervals of 500 m. Courtesy of Paul Taylor.

The Tonga Chronicle noted that the activity was first reported to Tonga Defense Services on 8 January by Carl Riechelmann, who had seen a plume coming from the site. On 12 January 1999 the Tonga Defence Services flew a photographic mission to record the reported appearance of a new island. Shortly after departing Tongatapu's Fua'amoto Airport in a Twin Beech equipped for surveillance operations, the crew sighted billowing white plumes from the volcano. The aircraft approached cautiously at 300 m altitude, made one circuit, then descended to 150 m for closer observation. The plane circled for almost an hour while a series of still photographs, as well as a video, were taken. During this time the crew noted that the island appeared to exhibit a pattern of rising, then receding. The island was estimated to be roughly 200-300 m long and 30-40 m wide. The crew also saw lava in a small vent that appeared to be located within a 100-m cone. The island was located at 20° 51.55'S, 175° 32.47'W (20.86°S, 175.54°W). Photographs and a report of their observations were posted on the website of Tonga Cable and Wireless.

Submarine activity continued on 14 January, with turbulent water present around a 40 x 300 m shoal, but no island was observed. Reports described a vent producing an ash-and-steam column and ejecting lava fragments, and floating pumice near the eruption site.

A precautionary Notice to Airmen (NOTAM) was issued to aviators on 14 January by the Nadi Aviation Control Center declaring an area within 5.5 km of the eruption site a danger area. Pilots were requested to report any signs of volcanic activity. Tongan officials also issued a warning to shipping transiting the area.

On 15 January a survey team, including two geologists from the Ministry of Land, Survey, and Natural Resources, inspected the island from the deck of the VOEA Savea, according to a report in the Tonga Chronicle. At that time the island had disappeared beneath the ocean surface, but the site was still emitting smoke and fumes. Because of possible danger, boats were warned to stay away.

Information Contacts: Paul W. Taylor, Australian Volcanological Investigations, PO Box 291, Pymble, NSW 2073, Australia (Email: avitaylor@peg.apc.org); Kelepi Mafi, Ministry of Lands, Survey, and Natural Resources, P.O. Box 5, Nuku'Alofa, Kingdom of Tonga; Tonga Cable and Wireless, Private Bag 4, Nuku'alofa, Kingdom of Tonga (URL: http://www.candw.to/); Tonga Chronicle, PO Box 197, Nuku'alofa, Kingdom of Tonga (URL: www.netstorage.com/kami/tonga/news); Tom Fox, International Civil Aviation Organization, 999 University Street, Montreal, Quebec H3C 5H7, Canada; Brad Scott, Wairakei Research Centre, Institute of Geological and Nuclear Sciences (IGNS) Limited, Private Bag 2000, Wairakei, New Zealand (URL: http://www.gns.cri.nz/, Email: bscott@gns.cri.nz).

An unnamed submarine volcano is located 35 km NW of the Niu Aunofo lighthouse on Tongatapu Island. Tongatapu is a coral island at the southern end of an island chain paralleling the Tofua volcanic arc on the east. The volcano, whose first documented eruptions took place in 1911 and 1923, was constructed at the southern end of a submarine ridge segment of the Tofua volcanic arc extending NNE to Falcon Island. Prior to an eruption in 1999, when an ephemeral island was formed, the volcano rose nearly 1400 m to within 13 m of the sea surface.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1999 Jan 8 (in or before) 1999 Jan 14 (?) Confirmed 1 Historical Observations
1923 Jul 1 Unknown Confirmed 0 Historical Observations
1911 Aug Unknown Confirmed 0 Historical Observations

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

Steam clouds and discolored water from a submarine eruption were observed in January 1999. This unnamed submarine volcano is located 35 km NW of the Niu Aunofo lighthouse on Tongatapu Island. The volcano, whose first documented eruptions took place in 1911 and 1923, was constructed at the southern end of a submarine ridge segment of the Tofua volcanic arc extending NNE to Falcon Island. An ephemeral island was formed during this eruption in 1999; prior to this the summit was 13 m beneath the sea surface.

Photo by B. Hutchins, 1999 (published in Taylor, 1999).

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

Richard J J, 1962. Kermadec, Tonga and Samoa. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 13: 1-38.

Smithsonian Institution-GVN, 1990-. [Monthly event reports]. Bull Global Volc Network, v 15-33.

Taylor P W, 1999. A volcanic hazards assessment following the January 1999 eruption of Submarine Volcano III Tofua volcanic arc, Kingdom of Tonga. Aust Volc Invest Occ Rpt, 99/01: 1-8.

Volcano Types

Submarine

Tectonic Setting

Subduction zone
Oceanic crust (< 15 km)

Rock Types

Major
No Data (checked)

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
0
0
0
88,571

Affiliated Databases

Large Eruptions of Unnamed Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.