Outcrops provide fundamental information for reconstructing eruptive history. Such information is important not only for geological studies, but also for outreach activity for reducing volcanic hazards. Nevertheless, it is difficult to construct an outcrop database. As a result, much outcrop information is unavailable to researchers. This paper describes the basic concept of general database systems and reviews the structure of conventional volcano databases in terms of information engineering. Based on these reviews, we clarify some issues with the conventional approach and present our new framework to solve them. To construct an outcrop database for volcanic geology, we propose a new framework that can manage various kinds of data with manually added tags, keywords or key-phrases, and automatically added tags, such as global positioning system information. This framework enables researchers and non-expert users, such as the public, to register new data easily because the database does not require a fixed input format or limit data notation on the entry into the database. It means that database users can contribute to constructing the database. Furthermore, our framework can deal with various types of data as stored data; thus, the database can handle many kinds of research material, ranging from raw data (primary data) to arranged data and research papers (more than secondary data). The framework also provides an application programming interface for easy construction of Web database applications. We also introduce several database applications based on our framework and supporting tools for researchers and non-experts. One of them is a web-based database application to manage research materials, such as photos and documents, for geologists. This application enables users to manage the material files using tags. Another is a Web-based database application called “Geo-Log”, which is used to collect and share outcrop information. Our framework can build a new outcrop database for volcanic geology as a knowledge infrastructure for collecting various research data from a wide range of users and apply the data to multi-purpose use, as a research material database for experts, education for reducing disasters, and as an information guide for Geopark visitors.
