The centre earlier warned “hazardous tsunami waves” were possible for coasts within 300 kilometres of the earthquake’s epicentre.
The quake struck 151 kilometres north-north-west of Santo on Vanuatu and was 35 kilometres deep, the US Geological Survey said.
The shallower a quake, the more damage it is likely to cause.
The USGS first measured the quake at 10 kilometres deep.
There were no immediate reports of damage.
Geoscience Australia senior seismologist Jonathan Bathgate said that while Port Olry residents were likely to have felt “very intense shaking”, “the likelihood was relatively low in terms of serious damage”.
He added that Port Vila residents would have “felt a shake but it probably wouldn’t be damaging at that distance”.
“Earthquakes such as this occur quite often in the area, so Vanuatu experiences these earthquakes of similar magnitudes probably fairly regularly,” Bathgate told AFP news agency.
Vanuatu is in the “Ring of Fire”, a zone of tectonic activity around the Pacific that is subject to frequent earthquakes and volcanic eruptions. - ABC