Raoul Island Volcano | John Seach


Kermadec Islands, New Zealand

29.27 S, 177.92 W
summit elevation 516 m

Raoul Island is triangular shaped, with a 3.3 km wide caldera. The island is the most northern, and largest of the Kermadec Islands. Raoul is the summit of a large submerged massif about 35 km by 20 km. The island covers 30 sq km in area (10 x 6km). Raoul island contains three lakes (Blue, Green, and Tui).

Eruptions at Raoul volcano have produced a complex history of events. A change from effusive to explosive eruptions occurred about 3700 years ago. Raoul Island is the only subareal volcano in the Kermadec Islands with series of felsic eruptions over a long time.

Raoul Island contains two collapse structures. Raoul Caldera is 3 x 2 km across and is located in the centre of the island; Denham Caldera (6 x 4 km) is in the western edge of the island and is mostly submarine.

2008 Earthquakes
A magnitide 6.5 earthquake hit 140 km SE of the volcano on 5th October 2008.
A magnitude 7.1 earthquake hit 70 km SSE of Raoul Island at 3:19 am on Tuesday 30th September 2008.

2006 Eruption
An eruption occurred at Raoul Island on 17th March 2006. The eruption destroyed about 12 acres of bush, and emitted boulders, rocks and ash. Ashfall covered half the island. A conservation worker who was measuring water temperature of Green Lake was killed during the eruption. The eruption was preceded by increased seismic activity.

1993 Unrest
Between 9-11 March 1993 more than 300 earthquakes were measured at the volcano, with maximum magnitude 4.3.

1964-65 Eruption
Rising pumice observed in Denham Caldera on 19–20 November 1964. In Raoul Caldera between November 1964 and January 1965: Discoloured water in Green Lake on 19th November, water-level 6 m above normal, new hot springs, 30 min phreatic eruption from craters on 21st November, mud and boiling water ejected untill early 1965.

1886 Eruption
In March 1886 pumice was observed rising from 240 m high seamount (summit -560 m), 7.5 km NE of Raoul Island.

1870 Eruption
Eruption in Denham caldera between June-October 1870 which destroyed two small islands which formed in 1814.

1853 Unrest
Tremors and fumes detected. Settlers in Denham Bay evacuated Raoul Island.

1814 Eruption
Between March and May 1814, an island 5 km in circumference emerged from 80 m deep water in Denham Caldera.

Further reading
Haase, K.M., Lima, S., Krumm, S. and Garbe-Schönberg, D., 2014. The magmatic evolution of young island arc crust observed in gabbroic to tonalitic xenoliths from Raoul Island, Kermadec Island Arc. Lithos210, pp.199-208.

Smith, I.E., Worthington, T.J., Price, R.C., Stewart, R.B. and Maas, R., 2006. Petrogenesis of dacite in an oceanic subduction environment: Raoul Island, Kermadec arc. Journal of volcanology and geothermal research156(3-4), pp.252-265.

Worthington, T.J., Gregory, M.R. and Bondarenko, V., 1999. The Denham caldera on Raoul Volcano: dacitic volcanism in the Tonga–Kermadec arc. Journal of Volcanology and Geothermal Research90(1-2), pp.29-48.

Healy, J., Lloyd, E.F., Banwell, C.J. and Adams, R.D., 1965. Volcanic eruption on Raoul island, November 1964. Nature205(4973), pp.743-745.

Raoul Island Volcano Eruptions

2006, 1964-65, 1886, 1870, 1814