The Japan Meteorological Agency said a tsunami as high as 3 metres (10 feet) could reach the country’s northeastern shoreline. By early Tuesday, the JMA reduced the warnings to advisories and later removed all advisories.

Japan Earthquake: Key points

• Officials at Japan’s Meteorological Agency have issued a warning for a possible ‘megaquake’ after Monday’s quake.
• The meteorological agency said the quake measured 7.5, after initially reporting it as 7.6. It issued an alert saying some places could see tsunami waves up to 3 metres (10 feet).
• Authorities later changed the tsunami warning to an advisory before lifting it.
• The centre of the quake was 80 km (50 miles) off the Aomori prefecture coast at a depth of 54 km.
• The US Geological Survey said another earthquake of magnitude 5.1 was recorded early Tuesday about 122 kilometres (76 miles) south of Honcho at a depth of 35 kilometres.
• Japan’s fire and disaster management agency said earlier that at least 23 people were injured. Public broadcaster NHK said most of the injuries happened when objects fell, and also said several people were injured in a hotel in Hachinohe.
• About 480 people were staying inside the Hachinohe Air Base, and 18 defence helicopters were sent out to check the extent of the damage, defence minister Shinjiro Koizumi said.
• Local media reported that around 200 passengers were stranded at New Chitose Airport in Hokkaido overnight.
• Japan’s Prime Minister Sanae Takaichi said that the government formed an emergency team to quickly evaluate the extent of the damage. Later, she asked people in the region to follow the latest updates from local offices.
• PM Takaichi also said in a briefing to reporters on Tuesday morning that about 30 people had been reported injured.
• This earthquake hit north of the area that faced the magnitude 9.0 quake and tsunami in 2011 that killed nearly 20,000 people and destroyed the Fukushima Daiichi nuclear power plant.
• Shortly after Monday’s earthquake, Tohoku Electric Power said in a post on X that the safety systems at its Higashidori nuclear power plant in Aomori and its Onagawa plant in the Miyagi region had not shown any abnormalities.
• Earthquakes are very difficult to predict, but in January a government panel slightly raised the chance of a large quake in the Nankai Trough off Japan in the coming 30 years to 75 to 82 percent.
• The government later issued a new projection in March saying that a “megaquake” and the tsunami that followed could lead to as many as 298,000 deaths and cause up to 2 trillion dollars in damage.
• Japan is one of the most earthquake-prone nations in the world. A tremor happens at least every five minutes. It sits in the ‘Ring of Fire’ of volcanoes and deep ocean trenches around the Pacific Basin and has about 20% of the world’s earthquakes of magnitude 6.0 or higher.