SANTIAGO, Chile (AP) – A powerful magnitude-8.3 earthquake shook Chile's capital Wednesday night, causing buildings to sway and people to take refuge in the streets. Several strong aftershocks hit within minutes as tsunami alarms sounded in the nearby port of Valparaíso.
There were no immediate reports on any injuries or damage, but communications were disrupted.
Chilean authorities issued a tsunami alert for the country's entire coast, and U.S. officials posted an alert for Hawaii. Chile's emergency office warned that big waves caused by the quake could hit the coast by 11 p.m.
The U.S. Geological Survey initially reported the quake at a preliminary magnitude of 7.9 but quickly revised the reading upward to 8.3. U.S. officials said the quake struck just offshore in the Pacific at 7:54 p.m. (6:54 p.m. EDT, 1154 GMT) and was centered about 141 miles (228 kilometers) north-northwest of Santiago. It said the quake was 4.8 miles (5 kilometers) below the surface.
A magnitude-8.8 quake and ensuing tsunami in central Chile in 2010 killed more than 500 people, destroyed 220,000 homes, and washed away docks, riverfronts and seaside resorts. That quake released so much energy, it actually it shortened the Earth's day by a fraction of a second by changing the planet's rotation.
Chile is one of the world's most earthquake-prone countries because just off the coast, the Nazca tectonic plate plunges beneath the South American plate, pushing the towering Andes cordillera to ever-higher altitudes.
The strongest earthquake ever recorded on Earth happened in Chile — a magnitude-9.5 tremor in 1960 that killed more than 5,000 people.