Scientists in Australia say two strong earthquakes struck near Vanuatu about the same time, but there are no reports of damage.
The first quake, measuring 7.3 on the Richter scale, occurred two minutes before the large quake jolted Japan.
Vanuatu's second quake, measuring 7.1, hit soon after.
Vanuatu police say there appears to be no damage, although buildings in the capital, Port Vila, were shaken.
