Possible Causes of Hydrothermal Eruptions

Abstract

Small hydrothermal eruptions occur in New Zealand every few years and there is evidence of very large ones in the past. There is no clear distinction between these, phreatic eruptions and phreatomagmatic eruptions because the detailed mechanics of these events is not clearly understood. Literature on natural explosions, explosions in engineering plant and the results of exploding a buried charge are reviewed and 3 physical processes that could be the cause of hydrothermal eruptions are identified. The collapse (condensation) of a steam zone offers the best explanation for small hydrothermal eruptions.