LONDON: The earthquakes in the Indian Ocean and the South Pacific occurred in a region of extraordinary geological activity called the Ring of Fire, which stretches from Indonesia to the coast of Chile. Several tectonic plates converge and create enormous pressure in the Earth’s crust. Nine out of 10 earthquakes in the world happen in the region.

It is unlikely the two latest earthquakes are connected, according to seismologists. They were caused by slippages in faults that took place 16 hours and 10,000km apart on two different tectonic plates.

The first earthquake, recorded as magnitude 8.0, happened on Tuesday at 6.48am local time around 200km off the coasts of Samoa and Tonga. Because the earthquake was only 10km beneath the Earth’s surface, it caused the seafloor to deform, triggering a tsunami that battered the Samoan capital of Apia. Most earthquakes in this particular region of the Ring of Fire are caused by the Pacific plate pushing underneath the Australia plate, but Tuesday’s quake was different.