A strong earthquake measuring 7.1 on the Richter scale hit the Southern Ocean near the remote Australian territory of Macquarie Island on Saturday.
There were no immediate reports of casualties or damages, the US Geological Survey said.
However, the Pacific Tsunami Warning Centre has not issued any tsunami warning.
The quake occurred at 11.30 am on Saturday (New Zealand time) and was centred beneath the open ocean, some 112 km southwest of Macquarie Island. The region is 755 km southwest of New Zealand's Auckland Island.