It's also the most active volcano on the continent and one of the active volcanic vents that's responsible for the formation of the island.
(It; 's also; the most active volcano on the continent and one of the active volcanic vents that's responsible for the formation of the island) (the most active volcano on the continent and one of the active volcanic vents; 's; responsible for the formation of the island)
It the most active volcano on the continent and one of the active volcanic vents
's also 's
the most active volcano on the continent and one of the active volcanic vents that's responsible for the formation of the island
responsible for the formation of the island