By Harry Petite

Sixteen tremors above magnitude 4.5 shook the Pacific 'Ring of Fire' on Monday

This followed a cluster of 53 quakes that hit the geological zone on Sunday

The quakes rattled Indonesia, Bolivia, Japan and Fiji, but failed to reach the US

Scientists have previously warned California is long overdue a major quake

Sixty nine major earthquakes have hit Earth's most active geological disaster zone in the space of just 48 hours.

Sixteen 'significant' tremors - those at magnitude 4.5 or above - shook the Pacific 'Ring of Fire' on Monday, following a spate of 53 that hit the region Sunday.

The quakes rattled Indonesia, Bolivia, Japan and Fiji, but failed to reach the western coast of the United States, which also falls along the infamous geological ring.

The tremors have raised concerns that California's 'Big One' - a destructive earthquake of magnitude 8 or greater - may be looming.

Scientists have previously warned that Ring of Fire activity may trigger a domino effect that sets off earthquakes and volcanic eruptions elsewhere in the region.

California, which straddles the huge San Andreas Fault Line and sits on the eastern edge of the ring, is long overdue a deadly earthquake, researchers claim.