Approximately 40,000 km long, the horseshoe shaped ring is the result of tectonic plate movement. Much of its boundaries consist of subduction zones, where one plate is pushed down into the Earth by a plate above becoming magma.
There is also a transform boundary between the Pacific and North American plates where the two rub against each other producing earthquakes.
Earlier this year Vanuatu saw Cyclones Judy and Kevin hitting back-to-back. On the same day that Kevin arrived two strong earthquakes were also recorded. Check out our coverage from the day below.