Fonualei

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  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 18.02°S
  • 174.325°W

  • 180 m
    590 ft

  • 243100
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

3 October-9 October 2001

The Laboratoire de Géophysique reported that explosive volcanic activity may have occurred at Fonualei volcano during late September. On 27, 28, and 30 September numerous short T waves were received by the French Polynesian Seismic Network. The preliminary location of the seismicity was determined to be near the Tonga archipelago at 18.18°S (well constrained) and 174°W (not as well constrained). The hydro-acoustic activity was interpreted to be volcanic and explosive and could not be related to seismic activity at the Tonga Trench. According to the Laboratoire de Géophysique, the hydro-acoustic source could be near Fonualei volcano.

Source: Laboratoire de Géophysique



 Available Weekly Reports


2001: October


3 October-9 October 2001

The Laboratoire de Géophysique reported that explosive volcanic activity may have occurred at Fonualei volcano during late September. On 27, 28, and 30 September numerous short T waves were received by the French Polynesian Seismic Network. The preliminary location of the seismicity was determined to be near the Tonga archipelago at 18.18°S (well constrained) and 174°W (not as well constrained). The hydro-acoustic activity was interpreted to be volcanic and explosive and could not be related to seismic activity at the Tonga Trench. According to the Laboratoire de Géophysique, the hydro-acoustic source could be near Fonualei volcano.

Source: Laboratoire de Géophysique


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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
[ 1974 Feb 16 ] [ Unknown ] Uncertain 1  
1957 Jun Unknown Confirmed   Historical Observations
1951 Aug 21 Unknown Confirmed 2 Historical Observations North-central part of the island
1939 Jun Unknown Confirmed 2 Historical Observations Summit, west and SE sides
1906 Mar Unknown Confirmed   Historical Observations
1846 Jun 11 (?) 1846 Oct 10 (in or after) Confirmed 4 Historical Observations
1791 Unknown Confirmed 2 Historical Observations
[ 1780 (in or before) ] [ Unknown ] Uncertain    

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. 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. Additional discussion of data sources can be found under Volcano Data Criteria.

Brodie J W, 1970. Notes on the volcanic activity at Fonualei Tonga. New Zeal J Geol Geophys, 13: 30-38.

Bryan W B, Stice G D, Ewart A, 1972. Geology, petrology, and geochemistry of the volcanic islands of Tonga. J Geophys Res, 77: 1566-1585.

Ewart A, Bryan W B, Gill J B, 1973. Mineralogy and geochemistry of the younger volcanic islands of Tonga, southwest Pacific. J Petr, 14: 429-465.

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

Spennemann D H R, 2003. The June 1846 eruption of Fonualei volcano, Tonga, an historical analysis. Charles Sturt Univ, The Johnstone Centre Rpt, 196: 1-30.

Taylor P W, Ewart A, 1997. The Tofua Volcanic Arc, Tonga, SW Pacific: a review of historic volcanic activity. Aust Volc Invest Occ Rpt, 97/01: 1-58.

The small, less than 2-km-wide island of Fonualei contains a fumarolically active crater, which is breached to the SW with a fresh lava flow extending to the sea and forming a rugged shoreline. Steep, inward-facing scarps mark the rim of a partially exposed caldera which contains a pyroclastic cone that is breached to the east and forms the 180-m-high summit of the island. Blocky lava flows from this cone fill much of the northern caldera moat and reach the sea through notches in the northern and eastern caldera rims. In contrast to the andesitic and basaltic rocks of other islands of the Tonga arc, Fonualei lavas are of dominantly dacitic composition. Eruptions have been recorded since 1791, with the largest taking place in June 1846, when explosive eruptions produced large pumice rafts, and ashfall damaged crops on the island of Vavua (56 km away) and fell on vessels up to 950 km distant. In 1939 explosive and effusive activity occurred from summit and flank vents, and water spouts were reported 1.6 km SE of the island.