This gives a representative 3-D view of how the tectonism of the Lesser Antilles is producing active volcanoes. The spreading ridge at the lower right is causing the growth of the subduction trench. This in turn causes melting of the overlying mantle and generation of upwelling magma. It is by this process that the entire volcanic arc, which is the Lesser Antillies (with the exception of Barbados) was formed.
Modified from National Geographic Society, Jan.1996.