Japan put on earthquake alert Authorities in Japan have warned of the heightened possibility of a ÒmegaquakeÓ in the coming days after a magnitude 7.5 tremor struck off the coast of the northern Aomori region Dec 8: At least 30 people injured after earthquake occurs about 80km off coast. Authorities warn of possible stronger tremor and urge public to remain on high alert for at least a week CHINA JAPAN NORTH KOREA RUSSIA SOUTH KOREA HOKKAIDO ISLAND HONSHU ISLAND Aomori Hachinohe Sapporo Sendai Tokyo PACIFIC OCEAN Sea of Japan (East Sea) 300km 185 miles Sources: BBC, USGS © GRAPHIC NEWS