Observations and models of volcanic eruption columns

Direct observations, satellite imagery and field studies of air-fall deposits provide a wealth of information about eruption column dynamics. These data have stimulated a wide range of theoretical, experimental and numerical models of eruption columns to expose the fundamental physical controls. These models show that the motion of hot, turbulent, particle-laden eruption columns is sensitive to the eruption velocity and mass flux, as well as the temperature and grain size distribution of the erupting material. In turn, the eruption velocity and mass flux are sensitive to the magma volatile content, the conduit radius and the chamber pressure. The importance of magma-water interactions, the crater geometry, ambient winds and the atmospheric stratification on the motion of the erupted material are also discussed. Predictions of the models are compared and contrasted and possible avenues for future research are suggested.