A 5.9 magnitude quake hit off Samoa but there have been no immediate reports of damage or injuries.
The quake struck at 11.45pm on Friday (local time) at a depth of 10km, the US Geological Survey said.
Its epicentre was 283km south of the Samoan capital Apia.
Samoa was devastated by huge waves that struck on 29 September after an 8.0 magnitude earthquake smashed into the southern coast of the most populated island of Upolu.
As a result 143 people were killed in Samoa while 32 were confirmed dead in neighbouring American Samoa and nine on Tonga's