Which ocean has a ring of volcanoes around it?
The Pacific Ocean.
Number of Volcanoes in the Ring of Fire 500 volcanoes comprise the Ring of Fire, a group of volcanoes that form more of a horseshoe than a ring along the coasts on both sides of the Pacific Ocean and extends to islands east of Australia. 75% of the world's active and dormant volcanoes are part of the Ring of Fire.
The ring of fire is a huge area comprising of many volcanoes in the pacific ocean, that accounts for approximately 80% of the world's seismic activity. It is a significant geological structure due to this, and contains a large majority of the world's volcanoes and volcanic activity. Contrary to it's name, the ring of fire is not actually a ring, but a horseshoe-shaped semi-ring.