(CNN) -- A strong 6.6-magnitude earthquake struck Sunday off the coast of Antarctica, prompting a warning that there was a "small possibility" it could trigger a tsunami.
The tremor was centered in waters south of South America's southern tip, about 334 miles (539 kilometers) west of Coronation Island and 388 miles northeast of Palmer Station in Antarctica, the U.S. Geological Survey reported.
It hit at 9:40 a.m. local time (8:40 a.m. ET) on Sunday, according to the federal agency, and had an estimated depth of 6.2 miles.
Afterward, the Pacific Tsunami Warning Center released a statement saying that there appears to be no threat of "destructive widespread tsunami" because of the quake.
But the agency did state "there is a small possibility of a local or regional tsunami that could affect coasts located usually no more than a few hundred kilometers from the earthquake epicenter.
"Authorities in the region near the epicenter should be made aware of this possibility," the warning center added.