SANTIAGO, April 2 (Reuters) - Thousands of people evacuated from Chile's low-lying coastal areas returned home on Wednesday morning after authorities called off a tsunami alarm as damage from a massive overnight earthquake seemed mostly limited.
The major earthquake, with a magnitude 8.2, struck off the coast of northern Chile on Tuesday, killing six and triggering a tsunami that pounded the shore with 2-meter (7-foot) waves.
Mines in Chile, the world No. 1 copper producer, appeared to be undamaged.
Angamos, a key copper exporting port in northern Mejillones, escaped major damage, but workers were evacuated as a precaution, port union leader Enrique Solar told Reuters.
The country's president, Michelle Bachelet, declared parts of Chile's north a disaster zone, promising troops and police reinforcements to maintain order while damage was repaired after landslides blocked roads.
Bachelet was scheduled to visit the affected areas later Wednesday.
Authorities were evaluating the full extent of damage.
Over 900,000 people were evacuated from the coastline along Chile. Many still have fresh memories of a deadly February 2010 quake and tsunami that struck the country's central-southern regions fresh in its memory.
An unusually large number of tremors that preceded Tuesday's quake unnerved residents, who emptied beaches, rushed to buy emergency rations, and prepared for an eventual evacuation.
"The government of Chile has been working hard to improve the awareness of people living along the coast to the threat from tsunamis and on what to do if one is approaching," said Steven Godby, an expert in disaster management at Nottingham Trent University in Nottingham, England.
"Several tsunami drills have taken place since the (earthquake and) tsunami that killed an estimated 500 plus Chileans in February 2010, and recent earthquakes in the region have helped to keep the threat firmly in people's minds," he added.
(Reporting by Anthony Esposito; Editing by Jeffrey Benkoe)