Vanuatu
Vanuatu (formerly called the New Hebrides Islands) is a line of volcanic
islands and submarine volcanoes 1,400 miles (2,300 km) east of northeast
Australia. There are 13 main islands, nine of which are home to active
volcanoes. Espiritu Santo and Malekula are older islands made of Miocene
(5-24 million years old) andesitic volcanic rocks. Volcanic rocks on Maewo
and Pentecost islands are also Miocene in age. Map with islands (names on
left) and volcanoes (names to right of islands) from Fisher (1957).
The geologically recent tectonic history of this region is complex. Colley
and Warden suggested that the Miocene volcanic rocks were related to
south-westward directed subduction. Present-day volcanism is related to the
north-eastward directed subduction
of the Australian Plate beneath the edge of the Pacific Plate. The two
plates converge at a rate of about 9 cm/year. A divergent plate boundary
(called a spreading center or spreading axis) is east of Vanuatu. Modified
from Monzier and others (1997).
Sources of information on the volcanoes of
Vanuatu (New Hebrides Islands).