One of the strongest earthquakes to hit the South Pacific in modern history triggered tsunami warnings in the ocean and forced thousands of people in New Zealand on Friday to evacuate coastal areas. Small tsunami waves were seen, but little damage occurred hours later.
The magnitude 8.1 earthquake in the Kermadec Islands region, about 620 miles from New Zealand, was the largest in a series of tremors over several hours, including two previous earthquakes that recorded magnitude 7.4 and magnitude 7.3.
The threat of the tsunami caused traffic jams and some chaos in New Zealand as people rushed to reach higher ground.
Residents recorded videos of small rising waves in some places, including Tokomaru Bay near Gisborne. In the afternoon, the National Emergency Management Agency said the threat had passed and people could return home, although they should continue to avoid the beaches.
George Novak / AP
One of the previous earthquakes struck much closer to New Zealand and woke many people as they felt a long, rumbling tremor. “I hope everyone is okay around here,” New Zealand Prime Minister Jacinda Ardern wrote on Facebook overnight.
After the biggest earthquake, New Zealand civil defense authorities told people in some coastal areas to immediately reach higher ground. They said a damaging tsunami was possible and the waves could reach up to 10 feet.
Emergency Management Minister Kiri Allan told reporters that people were following the advice.
“They felt the earthquakes long or hard and they knew how to grab the bag and head to the highlands,” he said. “I can only thank and acknowledge the tireless effort of the men and women of the up and down coast who knew how to act, when to act and what to do.”
The Pacific Tsunami Warning Center warned that the quake could cause tsunami waves of up to 10 feet in Vanuatu and up to 3 feet in Fiji, French Polynesia and as far away as Mexico and Peru.
1-foot waves were measured using ocean indicators in Vanuatu, New Zealand and the islands of Australia.
The U.S. Geological Survey said the strongest earthquake centered near the remote Kermadec Islands at a depth of 12 miles.
The agency said in a report that the quake occurred at the intersection of the Pacific and Australian tectonic plates and eclipsed the largest earthquake previously recorded in the region, a magnitude of 8.0 in 1976. It said that the interaction between the plates creates one of the most seismic. active regions of the world, and there have been 215 earthquakes above magnitude 6.0 over the past century.
Jennifer Eccles, an earthquake expert at the University of Auckland, said the quake was at the top of the scale for those who only affected the Earth’s oceanic crust.
“That’s almost as big as it gets,” he said.
He said most earthquakes larger than 8.0 in magnitude tend to occur when there is a more robust section of the continental crust.
The U.S. Geological Survey said the magnitude 7.4 earthquake was probably an “advantage” that contributed to the largest earthquake, but that the first earthquake to hit closer to New Zealand was too far in the time and distance for having contributed directly.
The first earthquake centered at a depth of 13 miles under the ocean, about 108 kilometers northeast of the city of Gisborne. It was widely heard in New Zealand and residents in the major cities of Auckland, Wellington and Christchurch reported that they were awake.
In 2011, a magnitude 6.3 earthquake struck the city of Christchurch, killing 185 people and destroying much of the city center.