Fishermen try to salvage their boats after an earthquake and tsunami that hit the northern port of Iquique, April 2, 2014. [Photo/Agencies]

Chileans live in one of the most earthquake-prone areas of the world. In 1960, southern Chile was hit by a 9.5 quake, the largest in modern history.

Residents in the area of the latest quake have been expecting "the big one" for many years. The Nazca and South American tectonic plates rub up against each other just off the coast of Iquique, where a "seismic gap" has been building up.

An unusually large number of tremors in the area in recent weeks had led authorities to reinforce emergency procedures, while residents bought rations and prepared for an eventual evacuation.

However, the mega-quake they had been fearing may still be yet to happen, said Paul Earle, a seismologist at the U.S. Geological Survey National Earthquake Information Center.

"This earthquake was not large enough to release the stress on the whole area where they believe the seismic gap is," he said.

"It's going to take some time to evaluate the effect of this earthquake on that region. But people should stay prepared."

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Major earthquakes in Chile's history