The National Emergency Management Agency and GNS Science are assessing whether an earthquake measuring magnitude 8.0 in the Drake Passage, a body of water south of Argentina, could generate a tsunami that might affect New Zealand.

The quake struck at 2.16pm on Friday.

Officials said that if a tsunami had been generated, it was not expected to arrive in New Zealand for at least eight hours.

The advisory was issued after a rapid assessment of preliminary earthquake information. Authorities said the situation could change as more information became available.

“Updates will be published on www.civildefence.govt.nz,” the agency said. “Only messages issued by the National Emergency Management Agency represent the official warning status for New Zealand.”