  In large-scale emergencies social media has become a key source of
information for public awareness, government authorities and relief agencies.
However, the sheer volume of data and the low signal-to- noise ratio limit the
effectiveness and the efficiency of using social media as an intelligence
resource. We describe Australian Crisis Tracker (ACT), a tool designed for
agencies responding to large- scale emergency events, to facilitate the
understanding of critical information in Twitter. ACT was piloted by the
Australian Red Cross (ARC) during the 2013-2014 Australian bushfires season.
  Video is available at: https://www.youtube.com/watch?v=Y-1rtNFqQbE
