Plinian eruption
Ambrym is a large basaltic volcano with a 12-km-wide caldera, and is one of the most active volcanoes of the New Hebrides volcanic arc. The caldera is the result of a huge Plinian eruption, which took place around AD 50. Its explosive force is rated 6, the third highest in the Smithsonian Institution's Volcanic Explosivity Index ranks of the largest volcanic explosions in recent geological history.