IQUIQUE, Chile (AP) — Hard-won expertise and a big dose of luck helped Chile escape its latest magnitude-8.2 earthquake with surprisingly little damage and death.

The country that suffers some of the world’s most powerful quakes has strict building codes, mandatory evacuations and emergency preparedness that sets a global example. But Chileans weren’t satisfied yesterday, finding much room for improvement. And experts warn that a “seismic gap” has left northern Chile overdue for a far bigger quake.

Authorities discovered just six reported deaths from the quake. It’s possible that other people were killed in older structures made of adobe in remote communities that weren’t immediately accessible, but it’s still a very low toll for such a powerful shift in the undersea fault that runs along the length of South America’s Pacific coast.

“How much is it luck? How much is it science? How much is it preparedness? It is a combination of all of the above. I think what we just saw here is pure luck. Mostly, it is luck that the tsunami was not bigger and that it hit a fairly isolated area of Chile,” said Costas Synolakis, an engineer who directs the Tsunami Research Centre at the University of Southern California.

Chile is one of the world’s most seismic countries and is particularly prone to tsunamis, because of the way the Nazca tectonic plate plunges beneath the South American plate, pushing the towering Andes cordillera ever higher.

About 2,500 homes were damaged in Alto Hospicio, a poor neighbourhood in the hills above Iquique, a city of nearly 200,000 people whose coastal residents joined a mandatory evacuation ahead of a tsunami that rose to only 8 feet (2.5 metres). Iquique’s fishermen poked through the aftermath: sunken and damaged boats that could cost millions of dollars to repair and replace.

Still, as President Michelle Bachelet deployed hundreds of anti-riot police and soldiers to prevent looting and round up escaped prisoners, it was clear that the loss of life and property could have been much worse.

The shaking that began at 8:46 pm Tuesday also touched off landslides that blocked roads, knocked out power for thousands, briefly closed regional airports and started fires that destroyed several businesses. Some homes made of adobe also were destroyed in Arica, another city close to the quake’s offshore epicentre.

The mandatory evacuation lasted for 10 hours in Iquique and Arica, the cities closest to the epicentre, and kept 900,000 people out of their homes along Chile’s 2,500-mile (4,000 kilometre) coastline. The order to leave was spread through cellphone text messages and Twitter, and reinforced by blaring sirens in neighbourhoods where people regularly practise earthquake drills.

Alberto Maturana, the former director of Chile’s Emergency Office, said Chileans were lucky the quake hadn’t caught them in the middle of the day when parents and children are separated, or in the middle of the night.

The US Geological Survey said more than 60 significant aftershocks, including one of magnitude 6.2, followed the Tuesday night quake centred 61 miles (99 kilometres) north-west of Iquique.

And seismologists warn that the same region is long overdue for an even bigger quake.