Note: Map shows the area with a shake intensity of 4 or greater, which U.S.G.S. defines as “light,” though the earthquake may be felt outside the areas shown. Source: U.S.G.S. By William B. Davis and John Keefe
A major, 7.4-magnitude earthquake struck in the South Atlantic Ocean on Friday, prompting an alert for a potential tsunami along parts of the Chilean coast, according to monitoring agencies in the United States.
The temblor happened at 8:58 a.m. Eastern about 136 miles south of Ushuaia, Argentina, in the Drake Passage, according to the United States Geological Survey.
“We are calling for the evacuation of the entire coastline of the Magallanes region. At this time, our duty is to take precautions and follow the instructions of the authorities,” President Gabriel Boric of Chile said on social media shortly after the earthquake.
Chilean officials later cancelled the evacuation order, but asked people to stay clear of beaches and boardwalks as a precaution. Schools in the region were closed for the day.
The U.S. Tsunami Warning System had issued a “tsunami threat” alert when the earthquake occured, but cancelled it shortly after noon. The agency noted that a small wave of about half a foot had been recorded by a sensor on the coast of Antarctica.
U.S.G.S. data earlier reported that the earthquake’s magnitude was 7.5.
As seismologists review available data, they may revise the earthquake’s reported magnitude. Additional information collected about the earthquake may also prompt U.S.G.S. scientists to update the shake-severity map.
Aftershocks in the region
An aftershock is usually a smaller earthquake that follows a larger one in the same general area. Aftershocks are typically minor adjustments along the portion of a fault that slipped at the time of the initial earthquake.
Quakes and aftershocks within 100 miles
Aftershocks can occur days, weeks or even years after the first earthquake. These events can be of equal or larger magnitude to the initial earthquake, and they can continue to affect already damaged locations.
When quakes and aftershocks occurred
Source: United States Geological Survey | Notes: Shaking categories are based on the Modified Mercalli Intensity scale. When aftershock data is available, the corresponding maps and charts include earthquakes within 100 miles and seven days of the initial quake. All times above are Eastern. Shake data is as of Friday, May 2 at 9:16 a.m. Eastern. Aftershocks data is as of Friday, May 2 at 7:44 p.m. Eastern.
Maps: Daylight (urban areas); MapLibre (map rendering); Natural Earth (roads, labels, terrain); Protomaps (map tiles)
