Destructive plate boundry, Atlantic plate is being forced under the Carribean plate. Creating friction and heat causing the rock to melt and a build up of magma which eventually leads to it being forced up, as a volcano.
The main eruption occurred on the 25th of June 1997. A smaller eruption occurred 18th of July 1995.
Montserrat is a small island located in the Caribbean and is a British colony with most residents rather poor living in small villages and farming.