We propose a phenomenological model for explosive water-melt interactions. Thermohydraulic fracturing was experimentally identified to be the main contributor to explosive energy release. We found experimental evidence that the model is applicable for a variety of melt compositions with very different thermal and rheological properties. The proposed mechanism does not require special premixing conditions. The pre-explosive geometries yielding the most intensive explosions were found to be cm to dm sized water domains entrapped by excess melt. First approximations to the thermal to kinetic energy conversion ratio show that the identified process can explain the occurence and the damage potential observed in industrial accidents and volcanic eruptions.

• Received 14 November 1997

DOI:https://doi.org/10.1103/PhysRevE.57.5726