<p>A 7.8-magnitude earthquake struck off the Japanese coast today, geologists said, shaking buildings in Tokyo and setting off car alarms.<br /><br /></p>.<p>Despite the huge power of the quake, there was no risk of a tsunami, The Pacific Tsunami Warning Centre reported.<br /><br />Residential buildings swayed for around a minute as the quake built in intensity at around 8.30pm (1130 GMT), an AFP correspondent reported.<br /><br />There were no immediate reports of injuries or damage.<br /><br />The epicentre was 676 kilometres below the Earth's surface. It was centred on a remote spot in the Pacific Ocean around 870 kilometres south of Tokyo, the US Geological Survey said.<br />Yoshiyuki Sasamoto, who runs a traditional guest house on Chichijima, one of the closest inhabited places to the epicentre, told NHK the shaking had been violent.<br /><br />"Initially a weaker quake hit and it stopped. Then the big one came. It was so strong that I couldn't stand still and couldn't walk," he said.<br /><br />Both runways at Narita Airport, the main international gateway to Tokyo, were temporarily closed while inspections were carried out. Trains in Tokyo were also temporarily halted and a football match in the city was briefly suspended.<br /><br />There were no reported abnormalities at any of the region's mothballed nuclear power plants.<br />A massive undersea quake that hit in March 2011 sent a tsunami barrelling into Japan's northeast coast.<br /><br />As well as killing thousands of people and destroying communities, the waves also swamped the cooling systems at the Fukushima nuclear plant, sending three reactors into meltdown.<br /><br />The nuclear disaster, the world's worst since Chernobyl, displaced tens of thousands of people and rendered tracts of land uninhabitable, possibly for decades.<br /><br />Today's rattle was the second sizable shake Tokyo has had this week, after a much less powerful -- but far shallower -- quake hit close to the capital on Monday.<br /><br />Japan sits at the meeting place of four tectonic plates and experiences around 20 per cent of the world's most powerful earthquakes every year.<br /><br />Yesterday a volcano in the far south of Japan erupted, spewing a huge column of ash high into the sky and forcing authorities to evacuate the island on which it sits.<br /><br />The eruption caused no injuries and no damage was reported, but it served as yet another reminder of the volatile geology of the country.</p>
<p>A 7.8-magnitude earthquake struck off the Japanese coast today, geologists said, shaking buildings in Tokyo and setting off car alarms.<br /><br /></p>.<p>Despite the huge power of the quake, there was no risk of a tsunami, The Pacific Tsunami Warning Centre reported.<br /><br />Residential buildings swayed for around a minute as the quake built in intensity at around 8.30pm (1130 GMT), an AFP correspondent reported.<br /><br />There were no immediate reports of injuries or damage.<br /><br />The epicentre was 676 kilometres below the Earth's surface. It was centred on a remote spot in the Pacific Ocean around 870 kilometres south of Tokyo, the US Geological Survey said.<br />Yoshiyuki Sasamoto, who runs a traditional guest house on Chichijima, one of the closest inhabited places to the epicentre, told NHK the shaking had been violent.<br /><br />"Initially a weaker quake hit and it stopped. Then the big one came. It was so strong that I couldn't stand still and couldn't walk," he said.<br /><br />Both runways at Narita Airport, the main international gateway to Tokyo, were temporarily closed while inspections were carried out. Trains in Tokyo were also temporarily halted and a football match in the city was briefly suspended.<br /><br />There were no reported abnormalities at any of the region's mothballed nuclear power plants.<br />A massive undersea quake that hit in March 2011 sent a tsunami barrelling into Japan's northeast coast.<br /><br />As well as killing thousands of people and destroying communities, the waves also swamped the cooling systems at the Fukushima nuclear plant, sending three reactors into meltdown.<br /><br />The nuclear disaster, the world's worst since Chernobyl, displaced tens of thousands of people and rendered tracts of land uninhabitable, possibly for decades.<br /><br />Today's rattle was the second sizable shake Tokyo has had this week, after a much less powerful -- but far shallower -- quake hit close to the capital on Monday.<br /><br />Japan sits at the meeting place of four tectonic plates and experiences around 20 per cent of the world's most powerful earthquakes every year.<br /><br />Yesterday a volcano in the far south of Japan erupted, spewing a huge column of ash high into the sky and forcing authorities to evacuate the island on which it sits.<br /><br />The eruption caused no injuries and no damage was reported, but it served as yet another reminder of the volatile geology of the country.</p>