Ground‐based measurement of ash distribution in volcanic plumes

Abstract

AbstractMeasurement of ash particle distribution within volcanic eruption plumes is important for volcanic hazard prediction, but is difficult because of the inherent danger and inaccessibility of volcanoes, and the three‐dimensional time‐dependent dynamics of turbulent eruption plumes. A combined study using a novel UV camera coupled with classical analysis of the dynamics of finite‐volume buoyant plumes has been used to develop a detection algorithm for ground‐based volcanic ash monitoring. The method provides the capability to observe and measure the internal structure of the plume, and processes occurring during plume rise, including concentration of ash over time into the plume ‘head’, increased ash at the plume edges during early formation and dilution at the top of the plume head as entrainment of surrounding air occurs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)