A newly refined electromagnetic technique has imaged the electrical structure of Vesuvius, and its success indicates it can be a very effective tool in forecasting volcano eruptions. The hope is to be able to gather enough data from active volcanoes to establish an adequate baseline of information for volcano surveillance and to better understand their structure.

Known as the long-offset transient electromagnetic (LOTEM) technique, its development has been made possible by modern modeling algorithms and higher computing power, both lacking in earlier electromagnetic work in the 1970s and 1980s. Such advances allow for analysis of complex topographic and three-dimensional (3-D) structures of volcanoes [A. Hördt and M. Müller, unpublished manuscript, 1999].