The chain is the tops of tall volcanoes that were produced by a hotspot , an opening in the ocean floor that periodically produces enough lava to make an island that breaks the ocean surface.
(The chain; is; the tops of tall volcanoes) (tall volcanoes; were produced; by a hotspot) (the ocean floor; produces; enough lava to make an island; T:periodically) (an island; breaks; the ocean surface)
The chain tall volcanoes the ocean floor an island
is were produced produces breaks
the tops of tall volcanoes
by a hotspot
enough lava to make an island T:periodically
the ocean surface