The quake struck at a depth of more than 200 kilometres (124 miles) at around 9:30am (2230 GMT Friday) some 130 kilometres north of Santo, USGS said.
“It's quite deep ... so there's no tsunami,” said David Jepsen, a seismologist with Geoscience Australia which measured the quake at 6.6 magnitude.
“I think it's well away from (the capital) Port Vila... but it's closer to some of the islands further to the northwest, but they would have had some moderate shaking really,” he told AFP.
The Hawaii-based Pacific Tsunami Warning Center said a destructive tsunami was not generated, based on the earthquake and historical tsunami data.
Vanuatu lies on the so-called “Pacific Ring of Fire”, a zone of frequent seismic activity caused by friction between shifting tectonic plates.
It has been rocked by several large quakes in recent years, averaging about three magnitude 7.0 or above incidents every year without any major damage.