Tsunami warnings have been issued across much of Japan's eastern coastline, with authorities urging residents in coastal, riverfront, and lakeside areas in several prefectures to evacuate to higher ground without delay.Re these:Another massive earthquake - magnitude 8.7, Russia east coastTsunami alert after Mag 8 earthquake off east coast of RussiaAlso:Tsunami Warning issued for the US state of Hawaii This article was written by Eamonn Sheridan at investinglive.com.