Abstract
The tone changes in mass media before and after the great east Japan earthquake on social problems were clarified quantitatively based on articles in newspapers about energy problem. Articles about energy problem were extracted from articles in two nationwide newspapers since 2010 to 2012, and frequently appeared words and co-occurrence patterns before and after the earthquake were analyzed. As a result, it is clarified that renewable energy was told form the viewpoint of ecology before the earthquake, but that was told from the viewpoint of power supply after the earthquake.
