Ambrym Island is a large basaltic volcano with a 12 km x 8 km wide caldera of the two active volcanic cones, Benbow and Marum.
Vanuatu 1980, map of Ambrym Island.
An erupting volcano on Ambrym Island is depicted below the map.
The stamp was issued in the series "1st Definitive Series — Maps of Vanuatu" and is existing inscribed in english "postage" on watermarked paper und in french "postes" on unwatermarked paper.
Vanuatu 1998, Marum and Bembow.