Japan Earthquake 2010: Strong Quake Prompts Tsunami Warning. Tsunami alert after Japan quake – Karameloo News U.K. A tsunami advisory has been issued in Japan after a 7.2 magnitude earthquake struck off the coast of Japan’s main island of Honshu, the Japan Meteorologica. Tsunami warning after 7.2 quake off Japan coast – CNN 7.2 magnitude quake prompts tsunami alert in Japan. Japan quake prompts tsunami alert – Tokyo/Jakarta – Powerful earthquakes hit northern Japan and eastern Indonesia Thursday, prompting tsunami warnings in two of the world’s most seismically active countries. A magnitude-7 quake struck off the Pacific coast of the Japanese island o Quake prompts tsunami alert – Quake prompts tsunami alert – World -. au 7.2 Magnitude Earthquake Hits Northern Japan, Tsunami Alert Issued Quake prompts tsunami alert in Japan CASSANO LAW FIRM A magnitude-6.8 earthquake, centered 17 kilometers below sea level, struck just off the northwestern Japanese coast Monday morning, knocking down several small buildings and resulting in at least 20.