Key Points:

• 7.4 magnitude earthquake struck northern Japan • Tsunami alerts were issued to wide areas of the east coast but were later lifted • Miyagi prefecture's Sendai Port was hit by a 1.4m wave • Depth of the quake recorded at 25km • Fukushima in tsunami warning zone, where waves of 90cm hit • Fukushima reactor 3 has been stablised and resumed cooling • Kiwis living in Japan react to quake • No connection between Japan and Kaikoura earthquake - scientist Coastal residents fled to higher ground as a powerful earthquake sent a series of moderate tsunamis toward Japan's northeastern shore today and fuelled concerns about the Fukushima nuclear power plant destroyed by a much larger tsunami five year ago. Lines of cars snaked away from the coast in the pre-dawn hours after authorities issued a tsunami warning and urged residents to seek higher ground immediately. The warning was lifted nearly four hours later. The magnitude 7.4 earthquake struck in the same region that was devastated by a tsunami in 2011, killing some 18,000 people. There were reports of minor injuries and damage, Japanese broadcaster NHK said. The earthquake shook buildings in Tokyo, 240km southwest of the epicenter. NHK also showed one person's video of water rushing up a river or canal, but well within the height of the embankment. It was eerily reminiscent of the 2011 disaster, when much larger tsunamis rushed up rivers and overflowed, wiping away entire neighborhoods.

Today, tsunami waves were recorded along the coast. The highest one was 1.4m (4.6 feet) in Sendai Bay. A tsunami advisory for waves of up to 1m (3 feet) remained in effect along the coast. The operator of the Fukushima Dai-ichi plant said there were no abnormalities observed at the plant, though a swelling of the tide of up to 1m was detected offshore. The plant was swamped by the 2011 tsunami, sending three reactors into meltdown and leaking radiation into the surrounding area. The plant is being decommissioned but the situation remains serious as the utility figures out how to remove still-radioactive fuel rods and debris and what to do with the melted reactor cores. Plant operator TEPCO said a pump that supplies cooling water to a spent fuel pool at the nearby Fukushima Dai-ni plant stopped working, but that a backup pump had been launched to restore cooling water to the pool. Both plants are run by Tokyo-based TEPCO. Naohiro Masuda, head of TEPCO's decommissioning unit, said he believes that the pump was shut off automatically by a safety system as the water in the pool shook. He said decommissioning work at the destroyed Dai-ichi plant had been temporarily suspended because of the earthquake. The Pacific Tsunami Warning Centre reported tsunami waves reaching between 0.3m and 1m above tide level were possible for some coasts of Japan. By 12.45pm (NZT), it said the tsunami threat had passed. Civil Defence reported there was no tsunami threat to New Zealand. The agency earlier reported it was assessing the threat.
Fukushima prefecture is north of Tokyo and home to the nuclear power plant that was destroyed by a huge tsunami following an offshore earthquake in 2011. Rugby player Cory Jane tweeted he had woken up to his room shaking. "Early wake up call to a 7.3 earthquake here in Japan. Room got to wiggling. Hope everyone is safe." The U.S. Geological Survey measured the magnitude at 6.9. - additional reporting from AP