Development and evaluation of a search support portal for public videos related to the great east Japan earthquake: “3.11 video portal – Great east Japan earthquake public footage finder”

Copious footage of the Great East Japan Earthquake (GEJE) was obtained during the disaster, and much of it is still available for viewing on the Internet. This makes up part of the big data that is important for grasping the reality of the GEJE. We aimed to help mainstream users reflect on what happened during the GEJE through video data that would help them visualize the situations, types, timing, and locations of associated damage to obtain correct knowledge and awareness about tsunamis and their associated damage, and to investigate evacuation actions. To this end, we developed a portal system called “3.11 Video Portal – Great East Japan Earthquake Public Footage Finder,” which can be used to search publicly available online videos of the GEJE and the consequent damage. This article reports the results of an access analysis following the launch of this system and an analysis of user surveys. Much of the footage is not linked to metadata on location, so this was added manually. We have seen a lot of access since launch, and have achieved a certain evaluation of the meaning or operability of this system. Furthermore, users commented about incorrect locational information, and tagging was accomplished through a collaborative effort. Based on the respon-dents’ feedback, we made a lot of technical revisions and confirmed the necessity of further refinement.