This paper analyzes the changes that the Great East Japan Earthquake of March 11 2011 brought on 1) information devices, 2) information sources, and 3) satisfaction and credibility toward the information source one year after the events took place. Data used in the analysis is obtained from an internet survey "Survey concerning changes in media use and information behavior one year after the earthquake" conducted on February 28, 2012. All survey participants representing the population composition of Metropolitan Tokyo who experienced the Great East Japan Earthquake (n=1034). The analysis showed that information behavior was not affected by the situations even though traditional communication infrastructure such as telephones did not function due to the earthquake and surging demand for evacuation information. satisfaction and credibility after one year showed more decline among those who had been using SNS before the earthquake. This trend was more significant among Twitter users. This suggests that The Great East Japan Earthquake of March11 temporarily put the information infrastructure into a chaotic situation. But the confusion was not prominent enough to encourage a change in information behavior, such as switching devices or information source; instead, the earthquake reinforced psychological aspects of information behavior.