Strong and shallow M6.6 earthquake hits near the coast of Atacama, Chile

A strong and shallow earthquake registered by the CSN Chile as M6.6 hit near the coast of Atacama, central Chile at 12:33 UTC (09:33 LT) on October 31, 2023. The agency is reporting a depth of 46 km (28 miles). USGS and EMSC are reporting M6.7 at a depth of 41 km (25 miles).

According to the USGS, the epicenter was located 102.5 km (63.7 miles) W of Vallenar, Atacama, and 144.2 km (89.6 miles) NNW of La Serena, Coquimbo, Chile.

18 000 people are estimated to have felt strong shaking, 62 000 moderate, and 841 000 light.

Based on earthquake information and historic tsunami records, the earthquake is not expected to generate a tsunami, NWS NTWC said.

The USGS issued a Green alert for shaking-related fatalities and economic losses. There is a low likelihood of casualties and damage.

Overall, the population in this region resides in structures that are resistant to earthquake shaking, though vulnerable structures exist. The predominant vulnerable building types are adobe block and rubble/field stone masonry construction.

Recent earthquakes in this area have caused secondary hazards such as landslides that might have contributed to losses.

The National Disaster Prevention and Response Service (Senapred) has classified the earthquake as a “medium intensity” event. Perception reports from Copiapó, Coquimbo, and La Serena indicate a grade VI on the Mercalli scale, which suggests noticeable shaking and potential minor damage in these areas.

The mayor of Coquimbo said the earthquake lasted between 40 and 45 seconds.

Power and water supply outages were reported.

Estimated population exposure to earthquake shaking

Selected cities exposed

Regional seismicity

Featured image credit: TW/SAM, Google