The power of using distributed architectures is well known in the scientific community. In the field of management of earth science related phenomena, distributed architectures such as grid computing, provide the required capability for data processing and storing. Originally, grid applications were mostly designed to be used by specialized users. Nowadays, developers are focused on to provide easy interaction systems for common (non-specialist) users. This paper presents the results of the usability study of a grid application for managing earth science phenomena. The results allowed determining the efficiency of a set of specific usability heuristics for evaluating grid computing applications.