Field data, including eruption movies, are used to construct a budget of the various modes of energy transport for the volcano Stromboli, Italy. At least eight distinct energy transport mechanisms can be identified. In its ''normal'' steady state eruption mode, Stromboli delivers approximately 1.1 Mw of power to the surface by energy transport mechanisms other than heat condiction; conducted heat probably is of the order of 6 Mw (for the part of the volcano above sea level). Convection is certainly an important mode as well and may exceed all the others, but we have no data to address the problem.

The energy budget for Stromboli, in its normal mode of activity appears to be dominated by heat conduction (and probably convection) through the surface of the ground (about 84% of the total). Heat content of the gas accounts for about 10% while the heat carried by condensed ejecta (lava fragments) and radiated heat from the vent, each contributes about 3%; the sum of all other modes is less than 1% (seismic, kinetic energy of ejecta, kinetic energy of gas, acoustic noise, heat carried in rare large flows).

Because there are at least 8 different energy transport mechanisms available and operating, we stress the importance of defining terms when comparisons are made between the energy release associated with different volcanic eruptions. The relative importance of different energy transport modes probably varies greatly both with eruption mechanism and site.