SANTIAGO — (UPDATE – 10:44 a.m.) A strong earthquake of magnitude 6.9 struck off the west coast of Chile on Monday, rocking the capital Santiago and briefly causing alarm along the Pacific Coast but sparing the quake-prone nation of any serious damage.
The quake was centered 22 miles (35 kilometers) west of the coastal city of Valparaiso at a shallow depth of 6.2 miles (10 km) below the sea, and about 85 miles (137 km) from Santiago, the US Geological Survey said.
“It was short but very powerful,” said Paloma Salamo, a 26-year-old nurse, who was in a clinic in Viña del Mar, just north of Valparaiso, when the quake struck.
People ran out of the facility carrying children and some headed for the hills when the tsunami alarm sounded, she said, but calm was soon restored.
Officials canceled a tsunami warning that had been issued in Valparaiso after the Chilean Navy and the Pacific Tsunami Warning Center said the quake was not expected to produce a dangerous seismic sea wave. The center reported small tsunami waves of half a foot.
There were no reports of structural damage in Valparaiso, but cellphone networks were down in some places, a spokesman with the local government in Valparaiso said.
“We have no reports of victims or significant damage. There have been some landslides in some places, without major complications,” said Interior Minister Mario Fernandez.
“In general the situation is pretty normal bearing in mind the quake’s intensity.”
Chile’s state-run Codelco, one of the largest copper mining companies in the world, said its operations were unaffected.
Anglo American, which has copper operations in central Chile, also said operations were normal.
A magnitude 7.1 quake is considered major and is capable of causing widespread and heavy damage, but the effects of this one would have been tempered because it was offshore.
Several aftershocks including two of magnitudes 5.0 and 5.4 were recorded in the same spot and could be felt in Santiago, part of a cluster of tremors from that area in recent days.
Chile, located on the so-called “Pacific Ring of Fire,” has a long history of deadly quakes, including a 8.8 magnitude quake in 2010 off the south-central coast, which also triggered a tsunami that devastated coastal towns. More than 500 people died.
That was the sixth-largest earthquake ever recorded, according to the USGS. The largest recorded temblor in history was also in Chile, a 9.5-magnitude quake in 1960.
A major 7.6 magnitude earthquake jolted southern Chile on Christmas Day 2016, prompting thousands to evacuate coastal areas, but no fatalities or major damage were reported in the tourism and salmon farming region.
The long, slender country runs along the border of two tectonic plates, with the Nazca Plate beneath the South Pacific Ocean pushing into the South America Plate, a phenomenon that also formed the Andes Mountains.