Inferring the geographic focus of online documents from social media   sharing patterns
  Determining the geographic focus of digital media is an essential first step for modern geographic information retrieval. However, publicly-visible location annotations are remarkably sparse in online data. In this work, we demonstrate a method which infers the geographic focus of an online document by examining the locations of Twitter users who share links to the document.   We apply our geotagging technique to multiple datasets built from different content: manually-annotated news articles, GDELT, YouTube, Flickr, Twitter, and Tumblr. 
Ryan Compton, Matthew S. Keegan, Jiejun Xu
cs.SI physics.soc-ph