Powerful M7.4 earthquake hits near the coast of Argentina, hazardous tsunami waves possible

The epicenter was located 222 km (138 miles) S of Ushuaia (population 56 825) and 334 km (208 miles) S of Rio Grande (population 52 681), Tierra del Fuego, Argentina.

1 000 people are estimated to have felt moderate shaking, and 284 000 light.

Based on the preliminary earthquake parameters, hazardous tsunami waves are possible for coasts located within 300 km (180 miles) of the earthquake epicenter, NWS PTWC said.

According to the updated tsunami threat forecast, tsunami waves reaching between 1 and 3 m (3.3 to 9.8 feet) above tide level are possible along some parts of the coast of Chile.

Tsunami waves reaching heights of 0.3 to 1 m (1 to 3.3 feet) above tide level are possible along some coastal areas of Antarctica.

It is important to note that actual wave amplitudes at the coast may differ from forecast values due to uncertainties in the model and the influence of local geographical features. In particular, maximum tsunami amplitudes observed on atolls or at locations with fringing or barrier reefs will likely be significantly lower than those indicated in the forecast.

For other regions within the coverage area of this advisory, a forecast has not yet been computed, PTWC said at 13:40 UTC.

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.

The USGS registered three strong aftershocks over the next 15 minutes — M5.4 at 13:07, M5.7 at 13:09, and M5.6 at 13:10 UTC, all three at a depth of 10 km (6.2 miles).

The Chilean Navy’s Hydrographic and Oceanographic Service (SHOA) issued a tsunami warning for the Magallanes and Chilean Antarctic Region. Chile’s National Disaster Prevention and Response Service (SENAPRED) ordered evacuations in coastal areas, including Puerto Williams, Puerto Natales, Porvenir, and Río Verde, as well as Antarctic bases Prat and O’Higgins. Approximately 1 800 people were evacuated from these areas.

In Argentina, authorities in Tierra del Fuego issued a temporary suspension of aquatic and navigation activities in the Beagle Channel and advised residents in coastal areas to remain vigilant.

An instrumental tsunami was recorded at Chile’s Prat Base in Antarctica, with a sea level variation of 6 cm (2.4 inches). The United States National Oceanic and Atmospheric Administration (NOAA) estimated potential wave heights of up to 1 m (3.3 feet) in Antarctica and between 1 m and 3 m (3.3 to 9.8 feet) along parts of the Chilean coast.

Later on May 2, Chilean authorities canceled the evacuation orders after determining that no significant tsunami had occurred. Residents were allowed to return to their homes, but officials advised continued caution near coastal areas.

Following the main earthquake, more than 50 aftershocks were recorded, the largest being a magnitude 6.4 event. These aftershocks did not trigger further tsunami concerns.

No casualties or significant damage to infrastructure have been reported in either Chile or Argentina. The earthquake was felt in various locations, including Punta Arenas and Timaukel in Chile, and Ushuaia, Tolhuin, and Río Grande in Argentina. The strongest perceived intensity was IV on the Mercalli intensity scale in Timaukel.

Estimated population exposure to earthquake shaking

Selected cities exposed

Regional seismicity

References:

¹ M7.4 earthquake Drake Passage, Argentina – USGS – May 2, 2025

² M7.4 earthquake Drake Passage, Argentina – EMSC – May 2, 2025

³ M7.5 earthquake Drake Passage, Argentina – PTWC – May 2, 2025