Notes on the 1964 eruption and the vegetation of Raoul Island
- Botany Division, Department of Scientific and Industrial Research, Christchurch
The sudden eruption of the Raoul Island volcano on 21 November 1964 abruptly terminated the Ornithological Society of New Zealand's. Expedition to the Kermadecs which had arrived only two days previously. The following observations are mostly little more than general impressions gained by the writer who was the botanist to the Expedition. The parts of the island visited were the north and east sides and the central crater area.
Raoul Island is the largest of the Kermadec group and lies just south of latitude 20¡ 15' S. and east of longitude 178¡W. Thus it is on the fringe of the subtropical region and has a mean annual temperature which averages 19.0¡C. Rainfall averages 59 inches per annum and is fairly well distributed. The total area is 7260 acres, of which nearly half is occupied by the large central caldera, in the bottom of which are three lakes. The whole island is of volcanic origin, and the andesitic rock, often overlaid with pumice, has generally resulted in a very rugged surface. The highest point, Moumoukai peak, is just under 1700 feet, and forms part of the mostly steep-sided rim of the caldera.