The snow-covered peak of the 2,402-foot (732-meter) Mount Usu erupted today, spewing black smoke and ash and forcing over 15,000 people from their homes. Historically one of Japan's most active volcanoes, Usu last erupted in 1978 after a number of earthquakes which formed a new and smaller volcano by its side. Mudslides triggered by that eruption killed three people in 1978, but so far no...