Tweet trend analysis in an emergency situation

The Great Eastern Japan Earthquake, which struck Japan on March 11, catastrophically affected all aspects of life: buildings, power plants, human life, etc. Moreover, it caused severe problems related to network infrastructure. We can ascertain the degree of network disorder from network traffic logs. Although we can infer what people did when the earthquake occurred on the Web from network traffic logs, we cannot know it precisely. Social media were used effectively during and after this earthquake, and they left a partial log revealing what people did on the Web during and after the earthquake. Such a log is one of the first logs of people's actions in a time of a catastrophic disaster. As described in this paper, we analyze Twitter logs and attempt to extract what happened in the emergency situation.