Media and Sentiments in the Great East Japan Earthquake Related Tweets -- Social Media as "Meta Media"

Around the time of the Great East Japan Earthquake, Twitter was put to use as an infrastructure to aid in obtaining information, functioning also as metamedia for sharing the flow of information from other media. The earthquake-related information included matters of questionable veracity, vicious rumors, and controversy, and evoked vigorous discussion and argument. In this study, we used tweet logs to analyze the emotions induced in the tweet contributors by the media, and thereby examine the psychological effects of the media on the contributors.