Update 9.40pm The National Advisory issued following the magnitude 7.7 earthquake near southeast of Loyalty Islands at 2.57pm NZT on May 19 is cancelled.

NEMA has been advised by GNS Science that tsunami wave activity has been observed at New Zealand coastlines over the course of this evening.

This activity has now significantly abated, enabling NEMA to issue this cancellation.

NEMA advises that some strong and unusual currents may still continue overnight and urges caution in affected beach and marine areas.

Update, 7.30pm: People have been warned to stay out of the sea around much of New Zealand's coastline after a magnitude 7.7 earthquake struck near the Loyalty Islands on Friday afternoon.

The warning has been issued by the National Emergency Management Agency - Nema, which says strong and unusual currents and unpredictable surges would continue for several hours on Friday night, and the threat must be regarded as real until the tsunami activity advisory is cancelled.

'Strong currents and surges can injure and drown people. There is a danger to swimmers, surfers, people fishing, and anyone in or near the water close to shore.”

Nema produced a map showing areas that are under threat of tsunami activity. Image: Nema.

People in or near the sea in the following areas should move out of the water, off beaches and shore areas and away from harbours, marinas, rivers and estuaries:

• The west coast of the North Island from Cape Reinga to Whanganui including the west coast of Auckland, Manukau Harbour and New Plymouth.
• The east coast of the North Island from Cape Reinga to Tolaga Bay including Whangārei, Great Barrier Island, the east coast of Auckland, Waiheke Island, Waitematā Harbour, Tauranga, Whakatāne and Ōpōtiki.
• The west coast of the South Island from Farewell Spit to Milford Sound including Westport, Greymouth and Hokitika.

Whanganui is expected to be the last place in New Zealand to be affected, with the first tsunami waves expected to arrive in the area about 8.30pm, although Nema cautioned that was provisional.

The US Pacific Tsunami Warning Centre says waves less than 50cm were measured off Lenakel, a port town in Vanuatu. Smaller waves were measured elsewhere off Vanuatu and off New Caledonia.

Vanuatu's National Disaster Management Office advised people to evacuate from coastal areas to higher grounds. The office says people should listen to their radios for updates and take other precautionary measures.

The Pacific Tsunami Warning Centre also said small waves were possible for Fiji, Kiribati, Papua New Guinea, Guam and other Pacific islands.

An official from Vanuatu's Meteorology and Geo-Hazards Department told Stuff the office had received calls from residents there who said they had felt shaking. The office had warned villagers on the southern islands to seek higher ground

New Zealand is about 2300km away from the Loyalty Islands, which are near New Caledonia, about 150km off its east coast.

The US Geological Survey (USGS) says the earthquake at 2.57pm struck at a depth of 38km.

Update, 5.25pm: A warning to expect "strong and unusual currents and unpredictable surges at the shore" has been issued by Nema after a magnitude 7.7 earthquake struck southeast of the Loyalty Islands at 2.57pm Friday afternoon.

Strong currents and surges can injure and drown people. There is a danger to swimmers, surfers, people fishing, and anyone in or near the water close to shore.

People in or near the sea in the following areas should move out of the water, off beaches and shore areas and away from harbours, marinas, rivers and estuaries.

AREAS UNDER THREAT: The West Coast of the North Island from CAPE REINGA to WHANGANUI including the West Coast of Auckland, Manukau Harbour and New Plymouth.

The East Coast of the North Island from CAPE REINGA to TOLAGA BAY including Whangarei, GREAT BARRIER ISLAND, the East Coast of Auckland, Waiheke Island, Waitemata Harbour, Tauranga, Whakatane and Opotiki.

The West Coast of the South Island from FAREWELL SPIT to MILFORD SOUND including Westport, Greymouth and Hokitika.

ADVICE FOR PEOPLE IN AREAS UNDER THREAT:

STAY OFF THE BEACHES AND SHORE AREAS

People on boats, liveboards and at marinas should leave their boats/vessels and move onto shore. Do not return to boats unless instructed by officials.

There is no need to evacuate other areas unless directly advised by local civil defence authorities. Coastal inundation (flooding of land areas near the shore) is not expected as a result of this event.

Nema is advising people to:

• Move out of the water, off beaches and shore areas and away from harbours, marinas, rivers and estuaries.
• Do not go to the coast to watch the unusual wave activity as there may be dangerous and unpredictable surges.
• Listen to local civil defence authorities and follow any instructions.
• Share this information with family, neighbours and friends.

The first tsunami activity causing these strong currents and surges was expected to reach New Zealand in the areas around North Cape at approximately 5pm New Zealand Standard Time and 5.45pm Chatham Islands Standard Time. This may be later and the first tsunami activity may not be the most significant.

Strong and unusual currents and unpredictable surges will continue for several hours and the threat must be regarded as real until this Advisory is cancelled.

This National Advisory has been issued following an assessment of information available. The situation may change as new information becomes available. Listen to the radio or TV for updates, or check www.civildefence.govt.nz

Update, 4.24pm: A warning of 'tsunami activity” has been issued by Nema after a magnitude 7.7 earthquake that struck near the Loyalty Islands on Friday afternoon.

'We expect New Zealand coastal areas to experience strong and unusual currents and unpredictable surges at the shore following a magnitude 7.7 earthquake southeast of Loyalty Island at 2.57pm," says a National Emergency Management Agency (Nema) spokesperson.

'Strong currents and surges can injure and drown people. There is a danger to swimmers, surfers, people fishing, and anyone in or near the water close to shore.

”People in or near the sea in the following areas should move out of the water, off beaches and shore areas and away from harbours, marinas, rivers and estuaries.”

Areas under threat:

The West Coast of the North Island from Cape Reinga to Whanganui including the West Coast of Auckland, Manukau Harbour and New Plymouth.

The East Coast of the North Island from Cape Reinga to Tolaga Bay including Whangarei, Great Barrier Island, the East Coast of Auckland, Waiheke Island, Waitemata Harbour, Tauranga, Whakatane and Opotiki.

The West Coast of the South Island from Farewell Spit to Milford Sound including Westport, Greymouth and Hokitika.

Advice for people in areas under threat:

STAY OFF THE BEACHES AND SHORE AREAS

People on boats, liveboards and at marinas should leave their boats/vessels and move onto shore. Do not return to boats unless instructed by officials.

There is no need to evacuate other areas unless directly advised by local civil defence authorities. Coastal inundation (flooding of land areas near the shore) is not expected as a result of this event. We are advising people to:

• Move out of the water, off beaches and shore areas and away from harbours, marinas, rivers and estuaries.
• Do not go to the coast to watch the unusual wave activity as there may be dangerous and unpredictable surges.
• Listen to local civil defence authorities and follow any instructions.
• Share this information with family, neighbours and friends.

The first tsunami activity causing these strong currents and surges may reach New Zealand in the areas North Cape at approximately 5pm pm May 19 2023 New Zealand Standard Time and 5.45pm Chatham Islands Standard Time. This may be later and the first tsunami activity may not be the most significant.

Strong and unusual currents and unpredictable surges will continue for several hours and the threat must be regarded as real until this Advisory is cancelled.

This National Advisory has been issued following an assessment of information available. The situation may change as new information becomes available. Listen to the radio or TV for updates, or check www.civildefence.govt.nz

Estimates of expected earliest wave arrival times:

Note: These times are provisional and based on the best information available. Arrival times may be as much as one hour later and may be adjusted in subsequent messages.

This map shows affected areas. Strong currents and surges can injure and drown people. People in or near the sea in these areas should move out of the water, off beaches and shore areas and away from harbours, marinas, rivers and estuaries. More info at https://t.co/ccVFYR8001 pic.twitter.com/klTgDFHh4C

— National Emergency Management Agency (@NZcivildefence) May 19, 2023

Earlier, 4pm: Civil Defence is assessing whether there is a tsunami threat for New Zealand after a magnitude 7.7 earthquake southeast of the Loyalty Islands.

In a tweet at 3.40pm on Friday, Civil Defence says if a tsunami was generated it wasn't likely to arrive in New Zealand for at least an hour.

The National Emergency Management Agency (Nema) and scientific advisors are still assessing the situation. It said it would issue an update as soon as possible.

The earthquake was a magnitude 7.7.

The Loyalty Islands are near to New Caledonia, approximately 150km off its East Coast.

The US National Tsunami Warning Center issued an alert for coasts within 1,000 kilometers (621 miles) of the epicentre which lay between Fiji, Vanuatu and New Caledonia.

Nema said only messages issued by it represented the official warning status for New Zealand.

The US Geological Survey (USGS) says the earthquake had a depth of 38 km.