Techniques for geolocating social media are described. According to an embodiment, information from textual content of a non-geolocated social media data item stored in a database is extracted. A knowledge database is then searched for a cluster of geo-located social media data items to which the information most closely relates, and an estimated location is assigned to the non-geolocated social media data item according to the cluster to which the information most closely relates. Each cluster comprises one or more representative tags for a spatio-temporal region. The knowledge database is created from geolocated social media data by grouping data according to location and extracting representative tags from the location's grouping of data according to textual content as well as information related to reliability and truthfulness of the textual content.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A method of geolocating social media, the method comprising: extracting information from textual content of a non-geolocated social media data item stored in a database; searching a knowledge database for a cluster of geo-located social media data items to which the information most closely relates; and assigning an estimated location to the non-geolocated social media data item according to the cluster to which the information most closely relates, wherein each cluster comprises one or more representative tags for a spatio-temporal region. 2. The method according to claim 1, wherein searching the knowledge database for the cluster comprises: comparing the information from the textual content of the non-geolocated social media data item to representative tags of each cluster in the knowledge base to determine a highest probable matching cluster. 3. The method according to claim 2, wherein assigning the estimated location to the non-geolocated social media data item comprises: assigning a location region of the highest probable matching cluster having a probability value above a threshold to the non-geolocated social media data item. 4. The method according to claim 1, wherein the textual content of the non-geolocated social media data item comprises tags, image descriptions and reader comments. 5. The method according to claim 1, further comprising creating the knowledge base from geolocated social media data stored in the database. 6. The method according to claim 5, wherein creating the knowledge base comprises: grouping the geolocated social media data into clusters according to location; and extracting representative tags from each cluster using textual content and information related to reliability and truthfulness of the textual content. 7. The method according to claim 6, wherein the information related to reliability and truthfulness of the textual content comprises at least one of frequency of use, ownership, and number of views. 8. The method according to claim 1, wherein the non-geolocated social media data item is an image or message posted to a social media network. 9. A system comprising: one or more processers; one or more computer readable media; a knowledge base creation and updating application stored on at least one of the one or more computer readable media that, when executed by at least one of the one or more processors, directs the at least one of the one or more processors to search at least one database comprising social media data having geo-coordinates and at least one associated tag; create location-based data clusters of the social media data using the geo-coordinates, extract at least one tag for each location-based cluster from the at least one associated tag of the social media data in that cluster, and store the at least one tag in association with geo-coordinates for that cluster in a knowledge base. 10. The system according to claim 9, wherein the knowledge base creation and updating application, when executed by at least one of the one or more processors, further directs the at least one of the one or more processors to create time-based groupings of the social media data for each location-based cluster. 11. The system according to claim 9, wherein the knowledge base creation and updating application, when executed by at least one of the one or more processors, further directs the at least one of the one or more processors to determine, for each location-based cluster, a deviation in date information associated with the social media data in that cluster. 12. The system according to claim 9, wherein, the at least one of the one or more processors is directed to extract at least one tag for each location-based cluster from the at least one associated tag of the social media data in that cluster creating the knowledge base by using textual content of the social media data and information related to reliability and truthfulness of the textual content. 13. The system according to claim 12, wherein the information related to reliability and truthfulness of the textual content comprises at least one of frequency of use, ownership, and number of views. 14. The system according to claim 9, further comprising: a geolocation assignment application stored on at least one of the one or more computer readable media that, when executed by at least one of the one or more processors, directs the at least one of the one or more processors to: extract information from textual content of a non-geolocated social media data item, search the knowledge base to determine at least one location-based cluster to which the information from the textual content relates, and append an estimated geocode to the non-geolocated social media data item according to the at least one cluster to which the information from the textual content relates. 15. The system according to claim 14, wherein the textual content of the non-geolocated social media data item comprises at least one of tags, image descriptions and reader comments. 16. The system according to claim 14, wherein the non-geolocated social media data item is an image or message posted to a social media network. 17. A system comprising: one or more computer readable media; instructions stored on at least one of the one or more computer readable media that, when executed by a processor, directs the processor to: extract information from textual content associated with a non-geolocated social media data item, search a knowledge base to determine at least one geocode to which the information from the textual content relates, and append an estimated geocode to the non-geolocated social media data item according to the at least one geocode to which the information from the textual content relates. 18. The system according to claim 17, wherein the instructions direct the processor to extract information from textual content associated with the non-geolocated social media data item by analyzing the textual content for recognizable entities and keywords, wherein the instructions direct the processor to search the knowledge base to determine the at least one geocode to which the information from the textual content relates by comparing the recognizable entities and keywords to information stored in the knowledge base. 19. The system according to claim 18, wherein the instructions further directs the processor to determine the at least one geocode to which the information from the textual content relates by computing coordinates, precision radius and probability within a radius for the recognizable entities and keywords using information stored in the knowledge base. 20. The system according to claim 17, wherein the textual content of the non-geolocated social media data item comprises at least one of tags, image descriptions and reader comments.