7.4 magnitude quake strikes southwest of Tonga

A 7.4-magnitude earthquake struck 255-km southwest of Tonga today, according to the US Geological Survey.

The under-sea quake struck at 5:19 A.M. Local time and sparked a tsunami alert, although no damage is expected due to its depth of 171-km, according to the Pacific Tsunami Warning Centre.

"A destructive tsunami was not generated, based on earthquake and historical tsunami data," the centre said.

The quake comes 12 days after a similar 6.5-magnitude earthquake struck the area, at a depth of 205-km.

Tonga, almost 2,000-km northeast of New Zealand, lies on the so-called Pacific "Ring of Fire", where continental plates collide causing frequent seismic activity.