A powerful magnitude-8.8 earthquake has struck off Russia's eastern Kamchatka Peninsula, sparking tsunami warnings and evacuations in nearby Japan, as well as other countries across the Pacific.
Japan's meteorological agency issued an alert for its Pacific coastline mid-morning on Wednesday, local time, warning tsunamis of up to 3 metres could hit the coast after waves of a similar size struck Russia's sparsely populated eastern regions.
Three tsunami waves had been recorded in Japan, the largest of which was 1.3 metres, officials said.
Japan's Chief Cabinet Secretary Yoshimasa Hayashi said there were no injuries or damage reported so far, and no irregularities at any nuclear plants.
Tsunami waves of between 1-3 metres can also cause flooding and damage wooden buildings, with people at risk of being killed by large drifting objects, according to the Japan Lifesaving Association.
The Japanese meteorological agency said the quake happened at 8:25am, local time, registering a preliminary magnitude of 8.0.
Soon afterwards, the US Geological Survey said it had recorded the quake at a depth of 19.3 kilometres with a magnitude of 8.7, later revising that reading to 8.8.
Japan’s Fire and Disaster Management Agency said nearly 2 million residents were under evacuation advisories in more than 220 municipalities along the Pacific coast from Hokkaido to Okinawa.
The epicentre of the quake itself was about 250 kilometres from Hokkaido, the northernmost of Japan's four large islands, and was felt only slightly in Japan, according to the NHK news agency.
Meteorological agency official Kiyomoto Masashi told a press conference that people needed to remember major waves could still arrive up to a day after the initial earthquake that caused them.
Tsunamis were able to repeatedly strike over an extended period of time, he said, and later waves could be much larger than earlier ones.
"I don't think we're expecting anything catastrophic," said the Hawaii-based International Tsunami Information Centre's director Laura Kong told the ABC.
While there had been damage reports from Russia, there hadn't been reports of waves "tens of metres high" anywhere, she said.
"The waves that are expected are probably going to be largest where we are in Hawaii," she said.
Warnings issued across the Pacific
Some tiny and low-lying Pacific island chains are among the world's most imperilled by tsunamis and rising seas.
The US Pacific Tsunami Warning Center said waves of up to 1.7 metres were impacting the Hawaiian islands.
Hawaii Governor Josh Green said no "waves of consequence" had hit Hawaii but all flights in and out of Maui had been cancelled.
Earlier, sirens sounded across the US island state and people were urged to evacuate to higher ground or emergency shelters, leading to traffic jams in Honolulu as people rushed to exit the city.
"If you stay on beaches, you could risk death," Mr Green warned.
The US National Tsunami Warning Center, based in Alaska, also issued a broader tsunami advisory for the continental United States, covering parts of Alaska, Washington, Oregon and California.
The US National Weather Service's San Francisco Bay Area branch posted a warning on X reminding Californians that tsunamis rarely arrived as a single wave.
Indonesian authorities warned that waves of less than 0.5 metres were expected to hit islands across its archipelago, urging communities to stay away from the coast and remain calm.
China issued a warning that waves between 0.3 and 1 metre were expected to hit parts of its east coast, while authorities in Taiwan, the Philippines, Canada and Mexico issued similar warnings.
China was dealing with gales and heavy rain from a tropical storm that made landfall earlier in the day, with more than 280,000 people evacuated from Shanghai.
Advisories were also in place for Papua New Guinea, Palau and Tonga, as well as the US territories of American Samoa, the Northern Marianas and Guam, where the first wave reached the coast on Wednesday afternoon.
Australia's Bureau of Meteorology said there was no tsunami threat for the Australian mainland or any of its islands or territories.
New Zealand authorities issued warnings of "strong and unusual currents and unpredictable surges" along coastlines throughout the country, but did not issue a tsunami warning.
Quake causes injuries, flooding in Russia's east
A state of emergency has been declared in Russia's eastern Kuril Islands, where a tsunami that followed this morning's earthquake damaged buildings and caused major flooding.
The port town of Severo-Kurilsk, home to about 2,500 people, was heavily inundated, with video posted on Russian social media showing buildings submerged in seawater.
Almost 3,000 of the islands' residents have been transported to safety, according to Russia's TASS news agency.
Waves of up to 4 metres were reported elsewhere in Russia.
In Petropavlovsk-Kamchatsky, the largest mainland city near the quake's epicentre with a population of around 180,000, TASS reported many people had run out into the street without shoes or outdoor clothing when the quake first struck.
Cabinets toppled inside homes, mirrors were broken, cars swayed in the street and balconies shook noticeably.
The Kamchatka region also experienced power outages as well as mobile phone service failures. However, telecommunications were restored after several hours.
The facade at the front of a kindergarten in Kamchatka collapsed during the quake, but no injuries were reported.
However, several people were injured at the region's airport, according to the regional health minister.
"Some were hurt while running outside, and one patient jumped out of a window," Oleg Melnikov told TASS.
Warnings awaken memories of Fukushima disaster
Japan, part of the geologically unstable area known as the Pacific Ring of Fire, is one of the world's most earthquake- and tsunami-prone countries.
Even faraway quakes can cause tsunamis to strike the island country when they occur at a shallow depth, according to Shinichi Sakai, a seismologist at the University of Tokyo.
Earlier in July, five powerful quakes — the largest with a magnitude of 7.4 — struck in the sea near Kamchatka.
This morning's quake appears to be the strongest earthquake recorded anywhere in the world since the 2011 magnitude-9.0 quake off north-eastern Japan that set off tsunamis and triggered a meltdown at the Fukushima nuclear power plant.
Workers at the plant, which is currently being decommissioned, were evacuated.
ABC/Wires
