The epicenters of all the seismic events were between the southern islands of Vanuatu and the northern coast of New Caledonia.
The strongest of the quakes registered a magnitude of 7.3 and was the most powerful recorded anywhere in the world so far this year.
Initial reports say there were no injuries or damage from any of the quakes.
Geophysicist Rafael Abreu from the U.S. Geological Survey said the epicenter region is where the Australia tectonic plate meets the New Hebrides plate, part of the so-called Ring of Fire.
