How events unfold: Spatiotemporal mining in social media

There has been significant recent interest in the application of social media analytics for spatiotemporal event mining. However, no structured survey exists to capture developments in this space. This paper seeks to fill this void by reviewing recent research trends. Three branches of research are summarized here---corresponding (resp.) to modeling the past, present, and future---information tracking and backward analysis, spatiotemporal event detection, and spatiotemporal event forecasting. Each branch is illustrated with examples, challenges, and accomplishments.