The work presented in this paper concerns Global Environment, focusing on Natural Risk Monitoring: our application is volcanic activity monitoring. The real-time data used in such a system generally comes from an array of sensors and are usually collected into a central database. With the now widespread addition of GPS, these data therefore have both temporal and spatial components. Therefore a major trouble encountered is the data structuring, so that it can store data effectively and process real-time queries on real-time objects. Our work offers a new indexing method dealing with multi-dimensional aspects of the data as well as storing and real-time querying